Formation of a Four-Membered Ring: From a Carbonyl-Conjugated Alkene

Handbook of Synthetic Photochemistry

Volumn , Issue , 2010, Pages 171-215

  Hehn, Jörg P ^a   Müller, Christiane ^a   Bach, Thorsten ^a  

^a TECHNICAL UNIVERSITY OF MUNICH   (Germany)

Author keywords

2+2 photocycloaddition; Cycloalkenone; Cyclobutane; Heterocycles; Photochemistry; Regioselectivity; Stereoselective synthesis; Total synthesis

Indexed keywords

EID: 84885745589     PISSN: None     EISSN: None     Source Type: Book    
DOI: 10.1002/9783527628193.ch6     Document Type: Chapter

References (155)

1. Ciamician, G. and Silber, P. (1908)Chemische Lichtwirkungen. Berichte der Deutschen Chemischen Gesellschaft,41, 1928-1935.
2. Hoffmann, N. (2008) Photochemical reactions as key steps in organic synthesis. Chemical Reviews, 108, 1052-1103.
3. Iriondo-Alberdi, J. and Greaney, M.F. (2007) Photocycloaddition in natural product synthesis. European Journal of Organic Chemistry, 4801-4815.
4. Margaretha, P. (2005) Photocycloaddition of Cycloalk-2-enones to Alkenes, in Organic Photochemistry (Molecular and Supramolecular Photochemistry), Vol. 12 (eds A.G. Griesbeck and J. Mattay), Marcel Dekker, New York, pp. 211-237.
5. Bach, T. (1998) Stereoselective intermolecular [2{thorn}2]-photocycloaddition reactions and their application in synthesis. Synthesis, 683-703.
6. Fleming, S.A., Bradford, C.L., and Gao, J.J. (1997) Regioselective and Stereoselective [2{thorn}2]-photocycloadditions, in Organic Photochemistry (Molecular and Supramolecular Photochemistry), Vol. 1 (eds V. Ramamurthy and K.S. Schanze), Marcel Dekker, New York, pp. 187-243.
7. Pete, J.-P. (1996) Asymmetric photoreactions of conjugated enones and esters, in Advances in Photochemistry, Vol. 21 (eds D.C. Neckers, D.H. Volman and Gv. Bunau), John Wiley & Sons, Inc., New York, pp. 135-216.
8. Mattay, J., Conrads, R., and Hoffmann, R. (1995) Formation of C-C bonds by light-induced [2{thorn}2] cycloadditions, in Methods of Organic Chemistry (Houben-Weyl), Vol. E21c (eds G. Helmchen, R.W. Hoffmann, J. Mulzer and E. Schaumann), Thieme, Stuttgart, pp. 3085-3132.
9. Crimmins, M.T. and Reinhold, T.L. (1993) Enone-olefin [2{thorn}2] photochemical cycloadditions, in Organic Reactions, Vol. 44, John Wiley & Sons Inc., New York, pp. 297-588.
10. Schuster, D.I. (2004) Mechanistic issues in [2{thorn}2] photocycloadditions of cyclic enones to alkenes, in CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn (eds F. Lenci and W.M. Horspool), CRC Press, New York, pp. 72.1-72.24.
11. Schuster, D.I., Lem, G.N., and Kaprinidis, A. (1993)New insights into an old mechanism: [2{thorn}2] photocycloaddition of enones to alkenes. Chemical Reviews,93, 3-22.
12. Srinivasan, R. and Hill Carlough, K. (1967)Mercury (3P1) photosensitized internal cycloaddition reactions in 1,4-,1,5-, and 1,6-dienes. Journal of the American Chemical Society,89, 4932-4936.
13. Liu, R.S.H. and Hammond, G.S. (1967) Photosensitized internal addition of dienes to olefins. Journal of the American Chemical Society, 89, 4936-4944.
14. Broeker, J.L., Eksterowicz, J.E., Belk, A.J., and Houk, K.N. (1995)On the regioselectivity of photocycloadditions of triplet cyclohexenones to alkenes. Journal of the American Chemical Society,117, 1847-1848.
15. Caldwell, R.A., Hrncir, D.C., Munoz, T. Jr, and Unett, D.J. (1996)Photocycloaddition of 4,4-dimethylcyclohexenone to 1,1-diphenylethylene. Evidence for a triplet exciplex intermediate. Journal of the American Chemical Society,118, 8741-8742.
16. Kaupp, G. and Ringer, E. (1990)Selektivitaten bei Photoadditionen an multifunktionelle Coffein-Derivate. Chemische Berichte,124, 339-345.
17. Maehr, H. (1985)A proposed new convention for graphic presentation of molecular geometry and topography. Journal of Chemical Education,62, 114-120.
18. Fox, M.A., Cardona, R., and Ranade, A.C. (1985)Effect of Cu(I) on cyclic enone photodimerisation. Journal of Organic Chemistry,50, 5016-5018.
19. Kosower, E.M., Wu, G.-S., and Sorensen, T.S. (1961)Effect of solvent on spectra. VI. Detection of the solvent effect on molecular conformation or shape through Z-values. Journal of the American Chemical Society,83, 3147-3154.
20. Grota, J., Domke, I., Stoll, I., Schröder, T., Mattay, J., Schmidtmann, M., Bögge, H., and Muller, A. (2005) Synthesis, fragmentation, and rearrangement reactions of annelated cyclobutylcarbinols. Synthesis, 2321-2326.
21. Termont, D., De Keukeleire, D., and Vandewalle, M. (1977) Regio-and stereoselectivity in [p2{thorn}p2] photocycloaddition reactions between cyclopent-2-enone and electron-rich alkenes. Journal of the Chemical Society, Perkin Transactions 1, 2349-2353.
22. Piers, E. and Orellana, A. (2001) Total synthesis of (±)-kelsoene. Synthesis, 2138-2142.
23. Mehta, G. and Srinivas, K. (2001)Enantioselective total syntheses of the novel tricyclic sesquiterpene hydrocarbons ({thorn})-and (-)-kelsoene. Absolute configuration of the natural product. Tetrahedron Letters,42, 2855-2857.
24. Mehta, G. and Sreenivas, K. (2002)Enantioselective total synthesis of the novel tricyclic sesquiterpene (-)-sulcatine G. Absolute configuration of the natural product. Tetrahedron Letters,43, 3319-3321.
25. Mehta, G. and Singh, S.R. (2006)Total synthesis of (±)-merrilactone A. Angewandte Chemie, International Edition,45, 953-955.
26. Mascitti, V. and Corey, E.J. (2006)Enantioselective synthesis of pentacycloanammoxic acid. Journal of the American Chemical Society,128, 3118-3119.
27. Zandomeneghi, M., Cavazza, M., and Pietra, F. (1984)Enantiomeric enrichment of cis-bicyclo[3.2.0]hept-3,6-dien-2-one with circularly polarized light via the photointerconversion of the enantiomers. Journal of the American Chemical Society,106, 7261-7262.
28. Ichikawa, M., Aoyagi, S., and Kibayashi, C. (2005)Total synthesis of (-)-incarvilline. Tetrahedron Letters,46, 2327-2329.
29. Crimmins, M.T., Pace, J.M., Nantermet, P.G., Kim-Meade, A.S., Thomas, J.B., Watterson, S.H., and Wagman, A.S. (2000)The total synthesis of (±)-ginkgolide B. Journal of the American Chemical Society,122, 8453-8463.
30. Lindemann, U., Reck, G., Wulff-Molder, D., and Wessig, P. (1998)Photocyclization of 4-oxo-4-phenyl-butanoyl amines to d-lactams. Tetrahedron,54, 2529-2544.
31. Ng, S.M., Bader, S.J., and Snapper, M.L. (2006)Solvent-controlled intramolecular [2{thorn}2] photocycloadditions of a-substituted enones. Journal of the American Chemical Society,128, 7315-7319.
32. Shipe, W.D. and Sorensen, E.J. (2006)Convergent, enantioselective syntheses of guanacastepenes A and E featuring a selective cyclobutane fragmentation. Journal of the American Chemical Society,128, 7025-7035.
33. Corey, E.J., Bass, J.D., LeMahieu, R., and Mitra, R.B. (1964)A Study of the photochemical reactions of 2-cyclohexenones with substituted olefins. Journal of the American Chemical Society,86, 5570-5583.
34. Schuster, D.I., Kaprinidis, N., Wink, D.J., and Dewan, J.C. (1991)Stereochemistry of [2 {thorn} 2] photocycloaddition of cyclic enones to alkenes: structural and mechanistic considerations in formation of trans-fused cycloadducts. Journal of Organic Chemistry,56, 561-567.
35. Maradyn, D.J. and Weedon, A.C. (1994)The photochemical cycloaddition reaction of 2-cyclohexenone with alkenes: trapping of triplet 1,4-biradical intermediates with hydrogen selenide. Tetrahedron Letters,35, 8107-8110.
36. Lange, G.L., Decicco, C.P., Willson, J., and Strickland, L.A. (1989) Ring expansions of [2{thorn}2] photoadducts. Potential applications in the synthesis of triquinane and taxane skeletons. Journal of Organic Chemistry, 54, 1805-1810.
37. Meyer, L., Alouane, N., Schmidt, K., and Margaretha, P. (2003)Photocycloaddition of cyclohex-2-enones to acrylonitrile. Canadian Journal of Chemistry,81, 417-422.
38. Morimoto, T., Horiguchi, T., Yamada, K., Tsutsumi, K., Kurosawa, H., and Kakiuchi, K. (2004) Acid-catalyzed rearrangement of an allenecyclohexenone photoadduct and its application in the synthesis of (±)-Pentalenene. Synthesis, 753-756.
39. Mehta, G. and Sreenivas, K. (2002)A new synthesis of tricyclic sesquiterpene (±)-sterpurene. Tetrahedron Letters,43, 703-706.
40. Srikrishna, A. and Ramasastry, S.S.V. (2005)Enantiospecific total synthesis of phytoalexins, ({thorn})-solanascone, ({thorn})-dehydrosolanascone, and ({thorn})-anhydro-b-rotunol. Tetrahedron Letters,46, 7373-7376.
41. Fujimori, T., Kasuga, R., Kaneko, H., Sakamura, S., and Noguchi, M. (1978) Solanascone: a novel sesquiterpene ketone from Nicotiana tabacum. X-Ray structure determination of the corresponding oxime. Journal of the Chemical Society, Chemical Communications, 563-564.
42. Lange, G.L., Decicco, C., Tan, S.L., and Chamberlain, G. (1985)Asymmetric induction in simple [2{thorn}2] photoadditions. Tetrahedron Letters,26, 4707-4710.
43. Herzog, H., Koch, H., Scharf, H.-D., and Runsik, J. (1986) Chiral induction in photochemical reactions V. Regio-and diastereoselectivity in the photochemical [2 {thorn} 2] cycloaddition of chiral cyclenone-carboxylates with 1,10-diethoxyethene. Tetrahedron, 42, 3547-3558.
44. Tsutsumi, K., Nakano, H., Furutani, A., Endou, K., Merpuge, A., Shintani, T., Morimoto, T., and Kakiuchi, K. (2004)Novel enhancement of diastereoselectivity of [2{thorn}2] photocycloaddition of chiral cyclohexenones to ethylene by adding naphthalenes. Journal of Organic Chemistry,69, 785-789.
45. Faure, S., Piva-Le-Blanc, S., Bertrand, C., Pete, J.-P., Faure, R., and Piva, O. (2002)Asymmetric intramolecular [2{thorn}2] photocycloadditions: a-and b-Hydroxy acids as chiral tether groups. Journal of Organic Chemistry,67, 1061-1070.
46. Muller, C. and Bach, T. (2008)Chirality control in photochemical reactions: enantioselective formation of complex photoproducts in solution. Australian Journal of Chemistry,61, 557-564.
47. Furutani, A., Katayama, K., Uesima, Y., Ogura, M., Tobe, Y., Kurosawa, H., Tsutsumi, K., Morimoto, T., and Kakiuchi, K. (2006)Asymmetric [2{thorn}2] photocycloaddition of cycloalkenonecyclodextrin complexes to ethylene. Chirality,18, 217-221.
48. Gilbert, A. (2004) 1,4-Quinone Cycloaddition Reactions with Alkenes, Alkynes, and Related Compounds, in CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn (eds F. Lenci and W.M. Horspool), CRC Press, New York, pp. 87-1-87-12.
49. Wilson, R.M. and Musser, A.K. (1980) Photocyclizations involving quinone-olefin charge-transfer exciplexes. Journal of the AmericanChemical Society,102,1720-1722.
50. Nicolaou, K.C., Vassilikogiannakis, G., Magerlein, W., and Kranich, R. (2001)Total synthesis of colombiasin A and determination of its absolute configuration. Chemistry-A European Journal,7, 5359-5371.
51. Nielsen, L.B. and Wege, D. (2006)The enantioselective synthesis of elecanacin through an intramolecular naphthoquinone-vinyl ether photochemical cycloaddition. Organic & Biomolecular Chemistry,4, 868-876.
52. Ward, D.E. and Shen, J. (2007)Enantioselective total synthesis of cyathin A3. Organic Letters,9, 2843-2846.
53. 3. Canadian Journal of Chemistry,82, 254-267.
54. Kokubo, K., Yamaguchi, H., Kawamoto, T., and Oshima, T. (2002)Substituent effects on the stereochemistry in the [2{thorn}2] photocycloaddition reaction of homobenzoquinone derivative with variously substituted alkenes and alkynes. Journal of the American Chemical Society,124, 8912-8921.
55. DeMayo, P. (1971)Enone photoannelation. Accounts of Chemical Research,4, 41-47.
56. Oppolzer, W. (1982)Intramolecular [2{thorn}2] photoaddition/cyclobutanefragmentation sequence in organic synthesis. Accounts of Chemical Research,15, 135-141.
57. Winkler, J.D., Bowen, C.M., and Liotta, F. (1995)[2{thorn}2] Photoaddition/Fragmentation strategies for the synthesis of natural and unnatural products. Chemical Reviews,95, 2003-2020.
58. Anklam, E., Ghaffari-Tabrizi, R., Hombrecher, H., Lau, S., and Margaretha, P. (1984)Synthesis and photochemistry of 2,2-dimethyl-3(2H)-thiophenone, a ketonic tautomer of 3-hydroxythiophene. Helvetica Chimica Acta,67, 1402-1405.
59. Margaretha, P. (1975)Zyklische Oxaenone: Untersuchungen mechanischer und stereochemischer Aspekte der [2{thorn}2]-Photocycloaddition von Enonen an Olefine. Chimia,29, 203-209.
60. Baldwin, S.W. and Mazzuckelli, T.J. (1986)Face selectivity in the [2{thorn}2]-photoannelation of chiral 3(2H)-furanones with alkenes. Tetrahedron Letters,27, 5975-5978.
61. Nicolaou, K.C., Wu, T.R., Sarlah, D., Shaw, D.M., Rowcliffe, E., and Burton, D.R. (2008) Total synthesis, revised structure, and biological evaluation of biyouyanagin a and analogues thereof. Journal of the American Chemical Society, 130, 11114-11121.
62. Gebel, R.-C. and Margaretha, P. (1992) Photochemical synthesis and some reactions of 7-oxa-and 7-thiatricyclo [3.2.1.03,6]octan-2-ones. Helvetica Chimica Acta, 75, 1633-1638.
63. Bach, T., Kemmler, M., andHerdtweck, E. (2003)Complete control of regioselectivity in the intramolecular [2{thorn}2] photocycloaddition of 2-alkenyl-3 (2H)-furanones by the length of the side chain. Journal of Organic Chemistry,68, 1994-1997.
64. Baldwin, S.W. and Wilkinson, J.M. (1979)Cyclohexenones by the photoannelation of alkenes with 2,2-dimethyl-3(2H)-furanone. Tetrahedron Letters,29, 2657-2660.
65. Patjens, J. and Margaretha, P. (1989)Photochemistry of ethyl 2,3-dihydro-2,2-dimethyl-3-oxo-1H-pyrrole-1-carboxylate. Helvetica Chimica Acta,72, 1817-1824.
66. Toda, J., Niimura, Y., Takeda, K., Sano, T., and Tsuda, Y. (1998) General method for synthesis of erythrinan and homoerythrinan alkaloids (1): synthesis of a cycloerythrinan, as a key intermediate to erythrina alkaloids, by Pummerer-type reaction. Chemical & Pharmaceutical Bulletin, 46, 906-912, and literature cited therein.
67. Sano, T., Toda, J., Tsuda, Y., Yamaguchi, K., and Sakai, S.-I. (1984)Dioxopyrrolines. XXXII. X-Ray determination of the molecular structure of a photoadduct of 2-trimethylsilyloxybutadiene to 3-ethoxycarbonyl-2-phenyl-D2-pyrroline-4,5-dione. Chemical & Pharmaceutical Bulletin,32, 3255-3258.
68. Bahaji, M. and Margaretha, P. (2007)Photocycloaddition of six-membered cyclic enones to propen-2-yl isocyanate. Helvetica Chimica Acta,90, 1455-1460.
69. Sato, M., Sunami, S., Kogawa, T., and Kaneko, C. (1994) An Efficient synthesis of cis-hydroindan-5-ones by novel modified de mayo reactions using 2,3-dihydro-4-pyrones as the enone chromophore. Chemistry Letters, 2191-2194.
70. Sabui, S.K. and Venkateswaran, R.V. (2004) Synthesis of heliannuol D, an allelochemical from Helianthus annus. Tetrahedron Letters, 45, 983-985.
71. Comins, D.L. and Williams, A.L. (2001)Model studies toward the total synthesis of the lycopodium alkaloid spirolucidine. Organic Letters,3, 3217-3220.
72. Guerry, P., Blanco, P., Brodbeck, H., Pasteris, O., and Neier, R. (1991)1-Methoxycarbonyl-substituiertes 2,3-Dihydropyridin-4(1H)-on (1/4 Methyl-1,2,3,4-tetrahydro-4-oxopyridin-1-carboxylat) als Chromophor fur die photochemische [2 {thorn} 2]-Cycloaddition. Helvetica Chimica Acta,74, 163-178.
73. Comins, D.L., Zheng, X., and Goehring, R. (2002)Total synthesis of the putative structureofthelupinalkaloidplumerinine. Organic Letters,4, 1611-1613.
74. Margaretha, P., Schmidt, K., Kopf, J., and Sinnwell, V. (2007) Photocycloaddition of 2,3-dihydro-2,2-dimethyl-4H-thiopyran-4-one (a 4-thiacyclohex-2-enone) to bonafide triplet quenchers. A contradiction? Synthesis, 1426-1433.
75. Hong, B.-C., Chen, S.-H., Kumar, E.S., Lee, G.-H., and Lin, K.-J. (2003)Intramolecular [2{thorn}2] photocycloaddition-fragmentation: facile entry to a novel tricyclic 5-6-7 ring system. Journal of the Chinese Chemical Society,50, 917-926.
76. Hoffmann, R.W. (1989)Allylic 1,3-strain as a controlling factor in stereoselective transformations. Chemical Reviews,89, 1841-1860.
77. Schulz, S.R. and Blechert, S. (2007)Palladium-catalyzed synthesis of substituted cycloheptane-1,4-diones by an asymmetric ring expanding allylation (AREA). Angewandte Chemie, International Edition,46, 3966-3970.
78. Shepard, M.S. and Carreira, E.M. (1997)Asymmetric photocycloadditions with an optically active allenylsilane: trimethylsilyl as a removable stereocontrolling group for the enantioselective synthesis of exo-methylenecyclobutanes. Journal of the American Chemical Society,119, 2597-2605.
79. Chen, C., Chang, V., Cai, X., Duesler, E., and Mariano, P.S. (2001)A general strategy for absolute stereochemical control in enone-olefin [2{thorn}2] photocycloaddition reactions. Journal of the American Chemical Society,123, 6433-6434.
80. Amougay, A., Pete, J.-P., and Piva, O. (1996) Réactions de photocycloadditions [2{thorn}2] intramoléculaire de N-alcénoyl-b-é naminones. Bulletin de la Société Chimique de France, 133, 625-635.
81. Berenjian, N., de Mayo, P., Sturgeon, M.-E., Sydnes, L.K., and Weedon, A.C. (1982)Biphasic photochemistry: micelle solutions as media for photochemical cycloadditions of enones. Canadian Journal of Chemistry,60, 425-436.
82. Kosugi, H., Sekiguchi, S., Sekita, R., and Uda, H. (1976)Photochemical cycloaddition reactions of a, b-unsaturated lactones with olefins, and application to synthesis of natural products. Bulletin of the Chemical Society of Japan,49, 520-528.
83. Alibĺs, R., Bourdelande, J.L., Font, J., Gregori, A., and Parella, T. (1996)[2 {thorn} 2] Photocycloaddition of homochiral 2(5H)-furanones to alkenes. First step for an efficient and diastereoselective synthesis of ({thorn})-and (-)-grandisol. Tetrahedron,52, 1267-1278.
84. Bertrand, S., Hoffmann, N., and Pete, J.-P. (1998) Photochemical [2 {thorn} 2] cycloaddition of cyclic enones to (5R)-5-menthyloxy-2[5H]-furanone. Tetrahedron, 52, 4873-4888.
85. Racamonde, M., Alibés, R., Figueredo, M., Font, J., and de March, P. (2008)Photochemical cycloaddition of mono-1,1-, and 1,2-disubstituted olefins to a chiral 2(5H)-furanone. Diastereoselective synthesis of ({thorn})-lineatin. Journal of Organic Chemistry,73, 5944-5952.
86. Inoue, M., Sato, T., and Hirama, M. (2006)Asymmetric total synthesis of (-)-merrilactone A: Use of a bulky protecting group as long-range stereocontrolling element. Angewandte Chemie, International Edition,45, 4843-4848.
87. Buu Hue, B.T., Dijkink, J., Kuiper, S.v., Schaik, S.v., Maarseveen, J.H., and Hiemstra, H. (2006) Synthesis of the tricyclic core of solanoeclepin a through intramolecular [2{thorn}2] photocycloaddition of an allene butenolide. European Journal of Organic Chemistry, 127-137.
88. Doroh, B. and Sulikowski, G.A. (2006)Progress toward the total synthesis of bielschowskys: a stereoselective [2{thorn}2] photocycloaddition. Organic Letters,8, 903-906.
89. Greenwood, E.S., Hitchcock, P.B., and Parsons, P.J. (2003)Studies towards a total synthesis of kainic acid. Tetrahedron,59, 3307-3314.
90. Albrecht, D., Basler, B., and Bach, T. (2008)Preparation and intramolecular [2{thorn}2]-photocycloaddition of 1,5-dihydropyrrol-2-ones and 5,6-dihydro-1H-pyridin-2-ones with C-, N-, and O-linked alkenyl side chains at the 4-position. Journal of Organic Chemistry,73, 2345-2356.
91. Wrobel, M.N. and Margaretha, P. (2003)Photocycloisomerization of Boc-protected 5-alkenyl-2,5-dihydro-1Hpyrrol-2-ones. Helvetica Chimica Acta,86, 515-521.
92. Sieburth, S.M. (2004) Photochemical reactivity of pyridones, in CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn (eds F. Lenci and W.M. Horspool), CRC Press, New York, pp. 103.1-103.18.
93. Lewis, F.D. and Barancyk, S.V. (1989)Lewis Acid catalysis of photochemical reactions. 8. Photodimerization and cross-cycloaddition of coumarin. Journal of the American Chemical Society,111, 8653-8661.
94. Hanifin, J.W. and Cohen, E. (1966)Some photochemical cycloaddition reactions of coumarin. Tetrahedron Letters,7, 1419-1424.
95. Suginome, H. and Kobayashi, K. (1988)A reinvestigation of a sensitized photochemical cycloaddition of coumarin with cyclopentene. Bulletin of the Chemical Society of Japan,61, 3782-3784.
96. Pfoertner, K.-H. (1976)84. Photoreaktionen von 3-substituierten Cumarinen. Helvetica Chimica Acta,59, 83-84.
97. Yamashita, M., Inaba, T., Nagahama, M., Shimizu, T., Kosaka, S., Kawasaki, I., and Ohta, S. (2005)Novel stereoconvergent transformation of 1,2a-disubstituted 1,2,2a,8b-tetrahydro-3H-benzo[b] cyclobuta[d]pyran-3-ones to 1,3-disubstituted 1,2,4a,9b-tetrahydrodibenzofuran-4-ols and its application to the second-generation synthesis of (±)-linderol A. Organic & Biomolecular Chemistry,3, 2296-2304.
98. Sakamoto, M., Kato, M., Aida, Y., Fujita, K., Mino, T., and Fujita, T. (2008) Photosensitized 2{thorn}2 cycloaddition reaction using homochirality generated by spontaneous crystallization. Journal of the AmericanChemicalSociety, 130, 1132-1133.
99. Akritopoulou-Zanze, I., Whitehead, A., Waters, J.E., Henry, R.F., and Djuric, S.W. (2007)Synthesis of novel and uniquely shaped 3-azabicyclo[4.2.0]octan-4-one derivatives by sequential Ugi/[2{thorn}2] ene-enone photocycloadditions. Organic Letters,9, 1299-1302.
100. Lewis, F.D., Reddy, G.D., Elbert, J.E., Tillberg, B.E., Meltzer, J.A., and Kojima, M. (1991)Spectroscopy and photochemistry of 2-quinolones and their Lewis acid complexes. Journal of Organic Chemistry,56, 5311-5318.
101. Evanega, G.R. and Fabiny, D.L. (1968)The photocycloaddition of carbostyril to olefins. Tetrahedron Letters,9, 2241-2246.
102. Evanega, G.R. and Fabiny, D.L. (1970)The photocycloaddition of carbostyril to olefins. The stereochemistry of the adducts. Journal of Organic Chemistry,35, 1757-1761.
103. Kobayashi, K., Suzuki, M., and Suginome, H. (1992)Photoinduced molecular transformation. 128. Regioselective [2 {thorn} 2] photocycloaddition of 3-acetoxyquinolin-2(1H)-one with alkenes and formation of furo[2,3-c]quinolin-4 (5H)-ones, 1-benzazocine-2,3-diones, and cyclopropa[d]benz[1]azepine-2,3-diones via a b-scission of cyclobutanoxyl radicals generated from the resulting [2{thorn}2] photoadducts. Journal of Organic Chemistry,57, 599-606.
104. Selig, P. and Bach, T. (2006)Photochemistry of 4-(20-aminoethyl) quinolones: enantioselective synthesis of tetracyclic tetrahydro-1aH-pyrido [40,30:2,3]-cyclobuta[1,2-c] quinoline-2,11 (3H, 8H)-diones by intra-and intermolecular [2{thorn}2] photocycloaddition reactions in solution. Journal of Organic Chemistry,71, 5662-5673.
105. Selig, P. and Bach, T. (2009) Total synthesis of meloscine by a [2 {thorn} 2]-Photocycloaddition/Ring expansion route. Chemistry-A European Journal, 15, 15, 3509-3525.
106. Bach, T., Bergmann, H., Grosch, B., Harms, K., and Herdtweck, E. (2001) Synthesis of enantiomerically pure 1,5,7-trimethyl-3-azabicyclo[3.3.1]nonan-2-ones as chiral host compounds for enantioselective photochemical reactions in solution. Synthesis, 1395-1405.
107. Breitenlechner, S., Selig, P., and Bach, T. (2007) Chiral organocatalysts for enantioselective photochemical reactions, in Ernst Schering Foundation Symposium Proceedings, vol. 2 (eds. M.T. Reetz, B. List, S. Jaroch and H. Weinmann), Springer-Verlag, Berlin, pp. 255-279.
108. Brandes, S., Selig, P., and Bach, T. (2004) Stereoselective intra-and intermolecular [2{thorn}2] photocycloaddition reactions of 4-(20-aminoethyl)quinolones. Synlett, 2588-2590.
109. Selig, P. and Bach, T. (2008)Enantioselective total synthesis of the melodinus alkaloid ({thorn})-meloscine. Angewandte Chemie, International Edition,47, 5082-5084.
110. Kaupp, G. (1975) Cycloadditionen zwischen ungleichen Olefinen, in Photochemie I (Houben-Weyl), Vol. IV/5 a (ed. E. Muller), Thieme, Stuttgart, pp. 360-412.
111. Birman, V.B. and Jiang, X.-T. (2004) Synthesis of sceptrin alkaloids. Organic Letters, 6, 2369-2371.
112. Inoue, M., Lee, N., Kasuya, S., Sato, T., Hirama, M., Moriyama, M., and Fukuyama, Y. (2007)Total synthesis and bioactivity of an unnatural enantiomer of merrilactone a: development of an enantioselective desymmetrization strategy. Journal of Organic Chemistry,72, 3065-3075.
113. Booker-Milburn, K.I., Cowell, J.K., Jiméenez, F.D., Sharpe, A., and White, A.J. (1999)Stereoselective intermolecular [2{thorn}2] photocycloaddition reactions of tetrahydrophthalic anhydride and derivatives with alkenols and alkynols. Tetrahedron,55, 5875-5888.
114. Gulten, S., Sharpe, A., Baker, J.R., and Booker-Milburn, K.I. (2007)Use of temporary tethers in the intramolecular [2{thorn}2] photocycloaddition reactions of tetrahydrophthalimide derivatives: a new approach to complex tricyclic lactones. Tetrahedron,63, 3659-3671.
115. Nishioka, Y., Yamaguchi, T., Kawano, M., and Fujita, M. (2008)Asymmetric [2{thorn}2] olefin cross photoaddition in a selfassembled host with remote chiral auxiliaries. Journal of the American Chemical Society,130, 8160-8161.
116. Scherer, O. and Kluge, F. (1966)Synthese von Dichlormaleinsaure-thioanhydrid und dessen Einsatz fur die Synthese der Thiophentetracarbonsaure. Chemische Berichte,99, 1973-1983.
117. Kiesewetter, R. and Margaretha, P. (1989)Photochemistry of thiophen-2(5H)-ones. Helvetica Chimica Acta,72, 83-92.
118. Anklam, E. and Margaretha, P. (1984) Synthese von Tetrahydro-3-thienylessigs aureestern durch konsekutive lichtinduzierte Reaktionen. Angewandte Chemie, 96, 360-361.
119. Karbe, C. and Margaretha, P. (1991) Photocycloadditions to 1-thiocoumarin. Journal of Photochemistry and Photobiology A: Chemistry, 57, 231-233.
120. Schwebel, D. and Margaretha, P. (2000)Photocycloaddition of 2H-1-benzopyran-3-carbonitriles and 2H-1-benzothiopyran-3-carbonitriles to alkenes and alkenynes. Helvetica Chimica Acta,83, 1168-1174.
121. Organ, M.G., Froese, R.D.J., Goddard, J.D., Taylor, N.J., and Lange, G.L. (1994)Photoadditions and dialkylcuprate additions to 2-tert-butyl-2,6-dimethyl-1,3-dioxin-4-one and related heterocycles. Experimental, ab initio theoretical, and X-ray structural studies of facial selectivity and enone pyramidalization. Journal of the American Chemical Society,116, 3312-3323.
122. Demuth, M., Palomer, A., Sluma, H.-D., Dey, A.K., Kruger, C., and Tsay, Y.-H. (1986)Asymmetric photocycloadditions with optically pure, spirocyclic enones. Simple synthesis of ({thorn})-and (-)-Grandisol. Angewandte Chemie, International Edition,25, 1117-1119.
123. Seebach, D., Zimmermann, J., Gysel, U., Ziegler, R., and Ha, T.K. (1988)Totally stereoselective additions to 2,6-disubstituted 1,3-dioxin-4-ones (chiral acetoacetic acid derivatives). Synthetic and mechanistic aspects of remote stereoselectivity. Journal of the American Chemical Society,110, 4763-4772.
124. Sato, M., Abe, Y., and Kaneko, C. (1990) Cycloadditions in syntheses. Part 47. 2-Monosubstituted 1,3-dioxin-4-ones: diastereofacial selectivity in pericyclic reactions and its explanation. Journal of the Chemical Society, Perkin Transactions 1, 1779-1783.
125. Murakami, M., Kamaya, H., Kaneko, C., and Sato, M. (2003)Synthesis of optically active 1,3-dioxin-4-one derivatives having a hydroxymethyl group at the 2-position and their use for regio-, diastereo-, and enantioselective synthesis of substituted cyclobutanols. Tetrahedron: Asymmetry,14, 201-215.
126. Winkler, J.D. and Doherty, E.M. (1999)The first total synthesis of (±)-saudin. Journal of the American Chemical Society,121, 7425-7426.
127. Winkler, J.D., Rouse, M.B., Greaney, M.F., Harrison, S.J., and Jeon, Y.T. (2002)The first total synthesis of (±)-ingenol. Journal of the American Chemical Society,124, 9726-9728.
128. Winkler, J.D., Harrison, S.J., Greaney, M.F., and Rouse, M.B. (2002) Mechanistic observations on the unusual reactivity of dioxenone photosubstrates in the synthesis of ingenol. Synthesis, 2150-2154.
129. Friedel, M.G., Cichon, M.K., and Carell, T. (2004) DNA damage and repair: photochemistry, in CRC Handbook of Organic Photochemistry and Photobiology, 2nd edn (eds F. Lenci and W.M. Horspool), CRC Press, New York, pp. 141.1-141.22.
130. Moriou, C., Thomas, M., Adeline, M.-T., Martin, M.-T., Chiaroni, A., Pochet, S., Fourrey, J.-L., Favre, A., and Clivio, P. (2007) Crystal structureandphotochemical behavior in solution of the 30-N-sulfamate analogue of thymidylyl(30-50)thymidine. Journal of Organic Chemistry, 72, 43-50.
131. Mondiére, A., Peng, R., Remuson, R., and Aitken, D.J. (2008)Efficient synthesis of 3-hydroxymethylated cis-and trans-cyclobutane b-amino acids using an intramolecular photocycloaddition strategy. Tetrahedron,64, 1088-1093.
132. Gauzy, C., Saby, B., Pereira, S., Faure, S., and Aitken, D.J. (2006) The [2{thorn}2] photocycloaddition of uracil derivatives with ethylene as a general route to cis-cyclobutane b-amino acids. Synlett, 1394-1398.
133. Fernandes, C., Gauzy, C., Yang, Y., Roy, O., Pereira, E., Faure, S., and Aitken, D.J. (2007) [2{thorn}2] photocycloadditions with chiral uracil derivatives: access to all four stereoisomers of 2-aminocyclobutanecarboxylic acid. Synthesis, 2222-2232.
134. Agócs, A., Batta, G., Jekö, J., and Herczegh, P. (2004) First synthesis of a dihydroorotidine analogue via a diastereoselective [2{thorn}2] photocycloaddition. Tetrahedron: Asymmetry, 15, 283-287.
135. Kemmler, M. and Bach, T. (2003)[2{thorn}2] photocycloaddition of tetronates. Angewandte Chemie, International Edition,42, 4824-4826.
136. Basler, B., Schuster, O., and Bach, T. (2005)Conformationally constrained bamino acid derivatives by intramolecular [2{thorn}2]-photocycloaddition of a tetronic acid amide and subsequent lactone ring opening. Journal of Organic Chemistry,70, 9798-9808.
137. Kemmler, M., Herdtweck, E., and Bach, T. (2004) Inter-and intramolecular [2{thorn}2]-photocycloaddition of tetronates-stereoselectivity, mechanism, scope and synthetic applications. European Journal of Organic Chemistry, 4582-4595.
138. Fleck, M., Yang, C., Wada, T., Inoue, Y., and Bach, T. (2007) Regioselective [2{thorn}2]-photocycloaddition reactions of chiral tetronates-influence of temperature, pressure, and reaction medium. Chemical Communications, 822-824.
139. Fleck, M. and Bach, T. (2008)Total synthesis of the tetracyclic sesquiterpene (±)-Punctaporonin C. Angewandte Chemie, International Edition,42, 6189-6191.
140. Redon, S. and Piva, O. (2006)Diastereoselective transannular [2{thorn}2] photocycloadditions of ascorbic acid derivatives. Tetrahedron Letters,47, 733-736.
141. Haywood, D.J., Hunt, R.G., Potter, C.J., and Reid, S.T. (1977) Photochemical transformations. Part 10. Photocycloaddition reactions of 4-hydroxycoumarin with cycloalkenes. Journal of the Chemical Society, Perkin Transactions 1, 2458-2461.
142. Haywood, D.J. and Reid, S.T. (1979)Intramolecular photocycloaddition reactions of 4-alkenyloxycoumarins. Tetrahedron Letters,20, 2637-2638.
143. Shimo, T., Tajima, J., Suishu, T., and Somekawa, K. (1991)Intramolecular photochemical reactions of 4-(walkenyloxy)-6-methyl-2-pyrones having an alkoxycarbonyl group at the olefinic carbon chain. Journal of Organic Chemistry,56, 7150-7154.
144. Miyauchi, H., Ikematsu, C., Shimazaki, T., Kato, S., Shinmyozu, T., Shimo, T., and Somekawa, K. (2008)One-pot synthesis of macrocyclic compounds possessing two cyclobutane rings by sequential interand intramolecular [2{thorn}2] photocycloaddition reactions. Tetrahedron,64, 4108-4116.
145. Bach, T., Bergmann, H., and Harms, K. (2000) Enantioselective intramolecular [2{thorn}2]-photocycloaddition reactions in solution. Angewandte Chemie, International Edition, 39, 2302-2304.
146. Bach, T. and Bergmann, H. (2000)Enantioselective intermolecular [2{thorn}2]-photocycloaddition reactions of alkenes and a 2-quinolone in solution. Journal of the American Chemical Society,122, 11525-11526.
147. Kaneko, C., Naito, T., and Somei, M. (1979) Synthesis of Cyclobuta[c]quinolin-3-ones. Intra-and inter-molecular photocycloadditions of 4-alkoxy-2-quinolone systems with olefins. Journal of the Chemical Society, Chemical Communications, 804-805.
148. Kaneko, C., Suzuki, T., Sato, M., and Naito, T. (1987)Cycloadditions in syntheses. XXXII. intramolecular photocycloaddition of 4-(w-alkenyloxy) quinolin-2(1H)-one: synthesis of 2-substituted cyclobuta[c]quinolin-3(4H)-ones. Chemical & Pharmaceutical Bulletin,35, 112-123.
149. Bach, T., Bergmann, H., Grosch, B., and Harms, K. (2002)Highly enantioselective intra-and intermolecular [2{thorn}2] photocycloaddition reactions of 2-quinolones mediated by a chiral lactam host: host-guest interactions, product configuration, and the origin of the stereoselectivity in solution. Journal of the American Chemical Society,124, 7982-7990.
150. Chiba, T., Kato, T., Yoshida, A., Moroi, R., Shimomura, N., Momose, Y., Naito, T., and Kaneko, C. (1984)Photocycloaddition of 2-quinolone and 2-pyridone derivatives to diketene: on the regioselectivity of the photoaddition. Chemical & Pharmaceutical Bulletin,32, 4707-4720.
151. Suginome, H., Kobayashi, K., Itoh, M., and Seko, S. (1990)Photoinduced molecular transformations. 110. Formation of furoquinolinones via b-scission of cyclobutanoxyl radicals generated from [2{thorn}2] photoadducts of 4-hydroxy-2-quinolone and acyclic and cyclic alkenes. X-ray crystal structure of (6aa,6bb,10ab,10ba)-(±)-10b-acetoxy-6a,6b,7,8,9,10,10a,10b-octahydro-5-methylbenzo[3,4]cyclobuta[1,2-c] quinolin-6(5H)-one. Journal of Organic Chemistry,55, 4933-4943.
152. Hook, B.D.A., Dohle, W., Hirst, P.R., Pickworth, M., Berry, M.B., and Booker-Milburn, K.I. (2005)A practical flow reactor for continuous organic photochemistry. Journal of Organic Chemistry,70, 7558-7564.
153. Inoue, Y. (2004) Enantiodifferentiating photosensitized reactions, in Chiral Photochemistry (Molecular and Supramolecular Photochemistry), Vol. 11 (eds Y. Inoue and V. Ramamurthy), Marcel Dekker, New York, pp. 129-177.
154. Inoue, Y. (2005)Light on chirality. Nature,436, 1099-1100.
155. Bauer, A., Westkamper, F., Grimme, S., and Bach, T. (2005)Catalytic enantioselective reactions driven by photoinduced electron transfer. Nature,436, 1139-1140.