Cyclization reactions of dianions in organic synthesis

Chemical Reviews

Volumn 104, Issue 9, 2004, Pages 4125-4149

  Langer, Peter ^a   Freiberg, Walter ^a  

^a UNIVERSITY OF GREIFSWALD   (Germany)

Author keywords

[No Author keywords available]

Indexed keywords

ALDEHYDES; BUTADIENE; BUTANE; CARBOXYLIC ACIDS; ESTERS; HYDROCARBONS; KETONES; SYNTHESIS (CHEMICAL);

CYCLIZATION REACTION; DIANIONS; DIMETHYL BUTADIENE; NITRILE DIANIONS; ORGANIC SYNTHESIS; OXALIC ACID; PHENYL SULFONE;

NEGATIVE IONS;

EID: 4644225203     PISSN: 00092665     EISSN: None     Source Type: Journal    
DOI: 10.1021/cr010203l     Document Type: Article

References (215)

1. Maercker, A. Methoden Org. Chem. (Houben-Weyl) 4. Aufl., Bd. E19d, 1993, 448;
2. Saalfrank, R. W. Methoden Org. Chem. (Houben-Weyl) 4. Aufl., Bd. E19d, 1993, 567;
3. Thompson, C. M.; Green, D. Tetrahedron 1991, 47, 4223;
4. Kaiser, E. M.; Petty, J. D.; Knutson, P. L. A. Synthesis 1977, 509;
5. Bates, R. B. in Buncel, E., Durst, T. Dianions and Polyanions, Comprehensive Carbanion Chemistry; Elsevier: Amsterdam, 1980; Part A, pp 1-53;
6. Petragnani, N.; Yonashiro, M. Synthesis 1982, 521;
7. Schleyer, P. von R. Pure Appl. Chem. 1983, 55, 355;
8. Thompson, C. M. Dianion Chemistry in Organic Synthesis; CRC Press: Boca Raton, 1994.
9. Langer, P. Chem. Eur. J. 2001, 7, 3858;
10. Langer, P.; Döring, M. Eur. J. Org. Chem. 2002, 221;
11. Langer, P. Synthesis 2002, 441.
12. Harris, T. M.; Harris, C. M. Tetrahedron 1977, 33, 2159.
13. Saalfrank, R. W.; Bauer, U.; Hilbig, K.; Welch, A. Chem. Ber. 1993, 126, 823;
14. Saalfrank, R. W.; Schütz, F.; Moenius, U. Synthesis 1985, 1062;
15. Saalfrank, R. W.; Rost, W., Angew. Chem. 1983, 95, 328;
16. Saalfrank, R. W.; Rost, W., Angew. Chem., Int. Ed. Engl. 1983, 22, 321;
17. Saalfrank, R. W.; Rost, W. Angew. Chem. 1985, 97, 870;
18. Saalfrank, R. W.; Rost, W. Angew. Chem., Int. Ed. Engl. 1983, 24, 855.
19. For the synthesis of open-chained products from 1,1-dianions, see Böhme, H.; Stammberger, W. Liebigs Ann. Chem. 1971, 56;
20. Kondo, K.; Tunemoto, D. Tetrahedron Lett. 1975, 17, 1397.
21. Tanaka, K.; Matsui, S.; Kaji, A. Bull. Chem. Soc. Jpn. 1980, 53, 3619.
22. Eisch, J. J.; Dua, S. K.; Behrooz, M. J. Org. Chem. 1985, 50, 3676.
23. Hendrickson, J. J.; Boudreaux, G. J.; Palumbo, P. S. J. Am. Chem. Soc. 1986, 108, 2358.
24. McCrombie, S. W.; Shankar, B. B.; Ganguly, A. K.; Padwa, A.; Bullock, W. H.; Dyszlewski, A. D. Tetrahedron Lett. 1987, 28, 4127.
25. Thomson, M. W.; Handwerker, B. M.; Katz, S. A.; Belser, R. B. J. Org. Chem. 1988, 53, 906, and references therein.
26. For a review of the structure of lithiated and dilithiated nitriles and sulfones, see Boche, G. Angew. Chem. 1989, 101, 286;
27. Boche, G. Angew. Chem., Int. Ed. Engl. 1989, 28, 277.
28. For the structure of α-cyanobenzyllithium in the solid state, see Boche, G.; Marsch, M.; Harms, K. Angew. Chem. 1986, 98, 373;
29. Boche, G.; Marsch, M.; Harms, K. Angew. Chem., Int. Ed. Engl. 1986, 25, 373. For the structure in solution, see
30. For the structure in solution, see Bauer, W.; Seebach, D. Helv. Chim. Acta 1984, 67, 1972.
31. For the structure in solution, see Das, R.; Wilkie, C. A. J. Am. Chem. Soc. 1972, 94, 4555.
32. For the structure ofa true α,α-dilithionitrile, see Zarges, W.; Marsch, M.; Harms, K.; Boche, G. Chem. Ber. 1989, 122, 1307.
33. Kaiser, E. M.; Solter, L. E.; Schwarz, R. A.; Beard, R. D.; Hauser, C. R. J. Am. Chem. Soc. 1971, 93, 4237.
34. Langer, P.; Freifeld, I. Org. Lett. 2001, 3903 and references therein.
35. For the preparation of cyclopropanes by reaction of silyl/sulfur-stabilized carbanions with epoxides, see Schaumann, E.; Friese, C. Tetrahedron Lett. 1989, 7033.
36. For the synthesis and reactions of silyl-substituted cyclopropanes, see Paquette, L. A.; Blankenship, C.; Wells, G. J. J. Am. Chem. Soc. 1984, 106, 6442;
37. Wells, G. J.; Yan, T.-H.; Paquette, L. A. J. Org. Chem. 1984, 49, 3604;
38. Blankenship, C.; Wells, G. J.; Paquette, L. A. Tetrahedron 1988, 4023.
39. Langer, P.; Döring, M. Synlett 1998, 396.
40. Langer, P.; Wuckelt, J.; Döring, M.; Görls, H. J. Org. Chem. 2000, 65, 3603.
41. Langer, P.; Anders, J. T.; Döring, M.; Görls, H. Eur. J. Org. Chem. 2001, 3953.
42. Langer, P.; Anders, J. T. Eur. J. Org. Chem. 2002, 686.
43. Langer, P.; Anders, J. T.; Weisz, K.; Jähnchen, J. Chem. Eur. J. 2003, 9, 3951
44. For the structure of α,o-dilithio sulfones, see Vollhardt, J.; Gais, H.-J.; Lukas, K. L. Angew. Chem. 1985, 97, 607;
45. Vollhardt, J.; Gais H.-J.; Lukas K.L. Angew. Chem., Int. Ed. Engl. 1985, 24, 608.
46. Gais, H.-J.; Vollhardt, J. Tetrahedron Lett. 1988, 29, 1529.
47. For the structure of a α,α-dilithio sulfone, see Gais, H.-J.; Vollhardt, J.; Lukas, K. L. Angew. Chem. 1985, 97, 607;
48. Gais, H.-J.; Vollhardt, J.; Lukas, K. L. Angew. Chem., Int. Ed. Engl. 1985, 24, 608.
49. Gais, H.-J.; Vollhardt, J.; Günther, H.; Moskau, D.; Lindner, H. J.; Braun, S. J. Am. Chem. Soc. 1988, 110, 978.
50. For the structure of monolithio sulfones, see Gais, H.-J.; Vollhardt, J.; Lukas, K. L. Angew. Chem. 1986, 98, 916;
51. Gais, H.-J.; Vollhardt, J.; Lukas, K. L. Angew. Chem., Int. Ed. Engl. 1986, 44, 939.
52. Craig, D.; Jones, P. S.; Rowlands, G. J. Synlett 1997, 1423;
53. Simpkins, N. S. Sulphones in Organic Synthesis; Pergamon: Oxford, 1993;
54. Craig, D.; McCague, R.; Potter, G. A.; Williams, M. R. V. Synlett 1998, 55;
55. Craig, D.; McCague, R.; Potter, G. A.; Williams, M. R. V. Synlett 1998, 58.
56. Mussatto, M. C.; Savoia, D.; Trombini, C.; Umani-Ronchi, A. J. Chem. Soc., Perkin Trans. 1 1980, 260.
57. Giblin, G. M. P.; Ramcharitar, S. H.; Simpkins, N. S. Tetrahedron Lett. 1988, 29, 4197.
58. Müller, J. F. K.; Neuburger, M.; Zehnder, M. Helv. Chim. Acta 1997, 80, 2182.
59. Eisch, J. J.; Dua, S. K.; Behrooz, M. J. Org. Chem. 1985, 50, 3674;
60. Crowley, P. J.; Leach, M. R.; Meth-Cohn, O.; Wakefield, B. J. Tetrahedron Lett. 1986, 27, 2909.
61. Langer, P.; Döring, M.; Seyferth, D. Chem. Commun. 1998, 1927;
62. Langer, P.; Döring, M.; Seyferth, D. Eur. J. Org. Chem. 2003, 1948;
63. For other work related to allene dianions, see Langer, P. Chem. Commun. 1999, 1217;
64. Langer, P.; Döring, M.; Seyferth, D.; Görls, H. Chem. Eur. J. 2001, 7, 573.
65. Bahl, J. J.; Bates, R. B.; Beavers, W. A.; Mills, N. S. J. Org. Chem. 1976, 41, 1620.
66. Maercker, A.; van de Flierdt, J., unpublished results, van de Flierdt, J.; dissertation, University of Siegen, 1990.
67. Pohmakotr, M.; Reutrakul, V.; Phongpradit, T.; Chansri, A. Chem. Lett. 1982, 687.
68. Furuta, K.; Misumi, A.; Mori, A.; Ikeda, N.; Yamamoto, H. Tetrahedron Lett. 1984, 25, 669.
69. Bilyard, K. G.; Garratt, P. J.; Hunter, R.; Lete, E. J. Org. Chem. 1982, 47, 4731.
70. Bilyard, K. G.; Garratt, P. J.; Underwood, A. J.; Zahler, R. Tetrahedron Lett. 1979, 20, 1815.
71. Noire, P. D.; Franck, R. W. Tetrahedron Lett. 1982, 23, 1031.
72. Doecke, C. W.; Garratt, P. J. J. Chem. Soc., Chem. Commun. 1981, 873.
73. Bilyard, K. G.; Garratt, P. J. Tetrahedron Lett. 1981, 22, 1755.
74. Garratt, P. J.; Porter, J. R. Tetrahedron Lett. 1987, 28, 351.
75. Corey, E. J.; Su, W.-G. Tetrahedron Lett. 1987, 28, 5241.
76. Misumi, A.; Iwanaga, K.; Furuta, K.; Yamamoto, H. J. Am. Chem. Soc. 1985, 107, 3343.
77. Furuta, K.; Ikeda, N.; Yamamoto, H. Tetrahedron Lett. 1984, 25, 675.
78. Koreeda, M.; Mislankar, S. G. J. Am. Chem. Soc. 1983, 105, 7203.
79. Tanaka, K.; Yamagishi, N.; Tanikaga, R.; Kaji, A. Chem. Lett. 1977, 471.
80. Langer, P.; Döring, M. Chem.. Commun. 1999, 2439.
81. Krapcho, A. P.; Dundulis, E. A. Tetrahedron Lett. 1976, 2205.
82. Bahl, J. J.; Bates, R. B.; Beavers, W. A.; Mills, N. S. J. Org. Chem. 1976, 41, 1620;
83. Bates, R. B.; Beavers, W. A.; Gordon, B., III; Mills, N. S. J. Org. Chem. 1979, 44, 3800;
84. Bates, R. B.; Gordon, B.; Keller, P. C.; Rund, J. V.; Mills, N. S. J. Org. Chem. 1980, 45, 168.
85. Yang, L. S.; Engler, T. A.; Shechter, H. J. Chem. Soc., Chem. Commun. 1983, 866.
86. Tanaka, N.; Kasai, T. Bull. Chem. Soc. Jpn. 1981, 54, 3020.
87. Priester, W.; West, R.; Chwang, T. L. J. Am. Chem. Soc. 1976, 98, 3;
88. Shimizu, T.; Hojo, F.; Ando, W. J. Am. Chem. Soc. 1993, 115, 3111.
89. Lin, J.; Pang, Y.; Young, V. G. Jr.; Barton, T. J. J. Am. Chem. Soc. 1993, 115, 3794.
90. Strohmann, C.; Lüdtke, S.; Wack, E. Chem. Ber. 1996, 129, 799.
91. Weiler, L. J. Am. Chem. Soc. 1970, 92, 6702.
92. For the extrusion of carbon monoxide in the reaction of glycols with oxalyl chloride, see Iida, T.; Itaya, T. Tetrahedron 1993, 49, 10511.
93. Sibi, M. P.; Marvin, M.; Sharma, R. J. Org. Chem. 1995, 60, 5016.
94. Langer, P.; Stoll, M. Angew. Chem. 1999, 111, 1919;
95. Langer, P.; Stoll, M. Angew. Chem., Int. Ed. 1999, 38, 1803.
96. Baldwin, J. E.; Kruse, L. I. J. Chem. Soc., Chem. Commun. 1977, 233.
97. For a review on the structure and reactivity of lithium enolates, see Seebach, D. Angew. Chem. 1988, 100, 1685;
98. Seebach, D. Angew. Chem., Int. Ed. Engl. 1988, 27, 1624.
99. For cyclizations of stabilized carbanions with oxalic acid dielectrophiles, see Saalfrank, R.; Nachtrab, J.; Reck, S.; Hampel, F. Z. Naturforsch. B, 1999, 54, 179;
100. Stachel, H.-D.; Zeitler, K. Arch. Pharm. (Weinheim) 1995, 328, 99;
101. 2 mediated cyclization of 1,3-dicarbonyl compounds with oxalyl chloride, see
102. Saalfrank, R. W.; Lutz, T. Angew. Chem. 1990, 102, 1064;
103. Saalfrank, R. W.; Lutz, T. Angew. Chem., Int. Ed. Engl. 1990, 29, 1041.
104. Langer, P.; Schneider, T.; Stoll, M. Chem. Eur. J. 2000, 6, 3204.
105. Langer, P.; Döring, M. Synlett 2001, 1437;
106. Anders, J. T.; Görls, H.; Langer, P. Eur. J. Org. Chem. 2004, 1897.
107. Yamaguchi, M.; Shibato, K. Tetrahedron 1988, 44, 4767.
108. Kashihara, H.; Shinoki, H.; Suemune, H.; Sakai, K. Chem. Pharm. Bull Japan 1986, 34, 4527.
109. Kraus, G. A.; Gottschalk, P. J. Org. Chem. 1983, 48, 2111.
110. Langer, P.; Freifeld, I. Chem. Commun. 2002, 2668.
111. Langer, P.; Holtz, E., unpublished results.
112. For reactions of 1,3,5-tricarbonyl compounds with glyoxal in aqueous alkaline solution, see Gawish, A.; Mitschka, R.; Cook, J. M. Tetrahedron Lett. 1981, 211.
113. Hampton, K. G.; Light, R. J.; Hauser, C. R. J. Org. Chem. 1965, 30, 1413.
114. Hampton, K. G.; Christie, J. J. J. Org. Chem. 1976, 41, 2772.
115. Langer, P.; Karimé, I. Synlett 2000, 743;
116. Langer, P.; Holtz, E.; Karimé, I.; Salch, N. N. R. J. Org. Chem. 2001, 66, 6057;
117. Langer, P.; Bellur, E. J. Org. Chem. 2003, 68, 9746.
118. For the formation of open-chained products, see Lambert, P. H.;6 Vaultier, M.; Carrié, R. J. Org. Chem. 1985, 50, 5352.
119. Sum, P.-E.; Weiler, L. Can. J. Chem. 1977, 55, 996; for the formation of open-chained products, see
120. Hoye, T. R.; Suhadolnik, J. C. Tetrahedron 1986, 42, 2855.
121. Langer, P.; Holtz, E. Angew. Chem. 2000, 112, 3208;
122. Langer, P.; Holtz, E. Angew. Chem., Int. Ed. 2000, 39, 3086;
123. Langer, P.; Holtz, E.; Saleh, N. N. R. Chem. Eur. J. 2002, 8, 917.
124. For cyclizations of monoanions, see Wang, T.; Chen, J.; Zhao, K. J. Org. Chem. 1995, 60, 2668;
125. Lavoisier, T.; Rodriguez, J. Synlett 1996, 339.
126. For π-allyl palladium complexes, see Trost, B. M. Angew. Chem. 1989, 101, 1199;
127. Trost, B. M. Angew. Chem., Int. Ed. Engl. 1989, 28, 1173; for a related reaction, see
128. Trost, B. M.; Runge, T. A. J. Am. Chem. Soc. 1981, 103, 7550.
129. Pound, M.; Davies, D. L.; Pilkington, M.; Pina Vaz Sousa, M. M.; Wallis, J. D. Tetrahedron Lett. 2002, 43, 1915;
130. O'Leary, J.; Colli, C.; Wallis, J. D. Synlett 2003, 675.
131. Hoffman, R. V.; Patonay, T.; Nayyar, N. K.; Tao, J. Tetrahedron Lett. 1996, 2381.
132. Bryson, T. A. J. Org. Chem. 1973, 38, 3428;
133. Mori, K.; Sasaki, M.; Tamada, S.; Suguro, T.; Masuda, S. Tetrahedron 1979, 35, 1601;
134. Yamaguchi, M.; Hirao, I. Chem. Lett. 1985, 337;
135. Lygo, B. Tetrahedron 1988, 44, 6889.
136. Kieczykowski, G. R.; Roberts, M. R.; Schlessinger, R. H. J. Org. Chem. 1978, 43, 788.
137. Al-Tel, T. H.; Voelter, W. J. Chem. Soc., Chem. Commun. 1995, 239;
138. Al-Tel, T. H.; Meisenbach, M.; Voelter, W. Liebigs Ann. 1995, 689.
139. Langer, P.; Freifeld, I.; Holtz, E. Synlett 2000, 501;
140. Langer, P.; Freifeld, I. Chem. Eur. J. 2001, 7, 565.
141. Nakada, M.; Iwata, Y.; Takano, M. Tetrahedron Lett. 1999, 9077.
142. Lygo, B. Synlett 1993, 765.
143. Seebach, D.; Ehrig, V. Angew. Chem. 1974, 86, 446;
144. Seebach, D.; Ehrig, V. Angew. Chem., Int. Ed. Engl. 1974, 13, 401.
145. Hirai, K.; Iwano, Y. Tetrahedron Lett. 1979, 2031.
146. Eskici, M.; Gallagher, T. Synlett 2000, 1360.
147. Langer, P.; Freifeld, I.; Armbrust, H., unpublished results. Axially chiral amides represent important building blocks for stereoselective alkylation reactions:
148. Curran, D. P.; Qi, H.; Geib, S. J.; DeMello, N. C. J. Am. Chem. Soc. 1994, 116, 3131;
149. Fujita, M.; Kitagawa, O.; Izawa, H.; Dobashi, A.; Fukaya, H.; Taguchi, T. Tetrahedron Lett. 1999, 1941, and references therein;
150. Kitagawa, O.; Fujita, M.; Kohriyama, M.; Hasegawa, H.; Taguchi, T. Tetrahedron Lett. 2000, 8539;
151. Godfrey, C. R. A.; Simpkins, N. S.; Walker, M. D. Synlett 2000, 388.
152. Langer, P.; Döring, Döring, M.; Görls, H.; Beckert, R. Liebigs Ann./Receuil 1997, 2553;
153. Langer, P.; Wuckelt, J.; Döring, M.; Beckert, R. Eur. J. Org. Chem. 1998, 1467, 7.
154. Langer, P.; Döring, M. Synlett 1998, 399;
155. Langer, P.; Döring, M.; Schreiner, P. R.; Görls, H. Chem. Eur. J. 2001, 7, 2617.
156. Katritzky, A. R.; Fali, C. N.; Li, J. J. Org. Chem. 1997, 62, 4148;
157. Meyers, A. I.; Loewe, M. F. Tetrahedron Lett. 1984, 25, 2641.
158. Langer, P.; Döring, M.; Seyferth, D. Synlett 1999, 135;
159. Langer, P.; Döring, M.; Görls, H. Eur. J. Org. Chem. 2001, 1511.
160. Baskaran, S.; Nagy, E.; Braun, M. Liebigs Ann./Recueil 1997,311.
161. Nokami, J.; Ono, T.; Kajitani, Y.; Wakabayashi, S. Chem. Lett. 1984, 707.
162. Witt, O.; Mauser, H.; Friedl, T.; Wilhelm, D.; Clark, T. J. Org. Chem. 1998, 63, 959;
163. Fox, M. A.; Chen, C.-C. J. Chem. Soc., Chem. Commun. 1985, 23.
164. Seyferth, D.; Wang, T.; Langer, P.; Ostrander, R. L.; Rheingold, A. L. Organometallics 1997, 16, 2413; see also
165. Seyferth, D.; Wang, T.; Davis, W. M. Organometallics 1994, 13, 4134.
166. Langer, P.; Döring, M.; Görls, H.,Eur. J. Org. Chem. 2001, 1511.
167. Tamura, Y.; Shindo, H.; Ishibashi, H. J. Heterocyclic Chem. 1980, 17, 1637;
168. Tamura, Y.; Shindo, H.; Uenishi, J.-I.; Ishibashi, H. Chem. Pharm. Bull. 1979, 27, 3186.
169. Tanaka, K.; Ootake, K.; Imai, K.; Tanaka, N.; Kaji, A. Chem. Lett. 1983, 633.
170. For the synthesis of 237 and related oxidative cyclizations, see Whitesides, G. M.; Gutowski, F. D. J. Org. Chem. 1976, 41, 2882.
171. Smith, J. G.; Talvitie, J. R.; Eix, A. R. E. J. Chem. Soc., Perkin Trans. 1 1975, 1474;
172. Cabiddu, S.; Cancelu, D.; Floris, C.; Gelli, G.; Melis, S. Synthesis 1988, 888.
173. Canonne, P.; Foscolos, G.; Lemay, G. J. Chem. Soc., Chem. Commun. 1979, 691;
174. Canonne, P.; Bernatchez, M. J. Org. Chem. 1986, 51, 2147;
175. Canonne, P.; Boulanger, R.; Chantegrel, B. Tetrahedron 1987, 43, 663;
176. Canonne, P.; Boulanger, R.; Bernatchez, M. Tetrahedron 1989, 45, 2525;
177. Canonne, P.; Boulanger, R.; Angers, P. Tetrahedron Lett. 1991, 32, 5861.
178. Cohen, T.; Ritter, R. H.; Ouellette, D. J. Am. Chem. Soc. 1982, 104, 7142;
179. Tanimoto, S.; Oida, T.; Hatanaka, K.; Sugimoto, T. Tetrahedron Lett. 1981, 22, 655.
180. Lansbury, P. T.; Spagnuolo, C. J.; Zhi, B.; Gritam, E. L. Tetrahedron Lett. 1990, 31, 3965.
181. Bates, R. B.; Gordon, B., III; Highsmith, T. K.; White, J. J. J. Org. Chem. 1984, 49, 2981.
182. Xiong, H.; Rieke, R. D. J. Org. Chem. 1989, 54, 3247;
183. Rieke, R. D.; Xiong, H. J. Org. Chem. 1991, 56, 3109.
184. Xiong, H.; Rieke, R. D. Tetrahedron Lett. 1991, 32, 5269;
185. Rieke, R. D.; Xiong, H. J. Org. Chem. 1992, 57, 6560;
186. Xiong, H.; Rieke, R. D. J. Am. Chem. Soc. 1992, 114, 4415.
187. Xi, Z.; Song, Q. J. Org. Chem. 2000, 65, 9157.
188. Xi, Z.; Song, Q.; Chen, J.; Guan, H.; Li, P. Angew. Chem., Int. Ed. 2001, 40, 1913;
189. Song, Q.; Chen, J.; JIn, X.; Xi, Z. J. Am. Chem. Soc. 2001, 123, 10419;
190. Chen, J.; Song, Q.; Li, P.; Guan, H.; Jin, X.; Xi, Z. Org. Lett. 2002, 4, 2269.
191. Maercker, A.; Daub, V. E. E., unveröffentlicht, Daub, V. E. E., Dissertation, Universität Siegen, 1992.
192. König, B.; Rödel, M.; Bubenitschek, P.; Jones, P. G. Angew. Chem. 1995, 107, 752;
193. König, B.; Rödel, M.; Bubenitschek, P.; Jones, P. G. Angew. Chem., Int. Ed. Engl. 1995, 34, 661.
194. Carlson, R. M.; Oyler, A. R. Tetrahedron Lett. 1975, 4099.
195. Iwai, K.; Kosugi, H.; Miyasaki, A.; Uda, H. Synth. Commun. 1976, 6, 357.
196. Bravo, P.; Carrera, P.; Resnati, G.; Ticozzi, C. J. Chem. Soc., Chem. Commun. 1984, 19.
197. Kende, A. S.; De Vita, R. J. Tetrahedron Lett. 1988, 29, 2521.
198. Kawabata, T.; Sumi, K.; Hiyama, T. J. Am. Chem. Soc. 1989, 111, 6843.
199. Matsumura, N.; Kunugihara, A.; Yoneda, S. Tetrahedron Lett. 1983, 24, 3239;
200. Matsumura, N.; Kunugihara, A.; Yoneda, S. Tetrahedron Lett. 1984, 25, 4529.
201. Beam, C. F.; Reames, D. C.; Harris, C. E.; Dasher, L. W.; Hollinger, W. M.; Shealy, N. L.; Sandifer, R. M.; Perkins, M.; Hauser, C. R. J. Org. Chem. 1975, 40, 514.
202. Duncan, D. C.; Trumbo, T. A.; Almquist, C. D.; Lentz, T. A.; Beam, C. F. J. Heterocyclic Chem. 1987, 24, 555.
203. Lansbury, P. T.; Spagnuolo, C. J.; Zhi, B.; Grimm, E. L. Tetrahedron Lett. 1990, 31, 3965.
204. Bates, R. B.; Gangwar, S.; Kane, V. V.; Suvannachut, K.; Taylor, S. R. J. Org. Chem. 1991, 56, 1696.
205. Thompson, C. M.; Frick, J. A. J. Org. Chem. 1989, 54, 890.
206. Thompson, C. M. Tetrahedron Lett. 1987, 28, 4243.
207. Thompson, C. M.; Green, D. L. C.; Kubas, R. J. J. Org. Chem. 1988, 53, 5389.
208. Thompson, C. M.; Frick, J. A.; Woytowicz, C. E. Synth. Commun. 1988, 18, 889.
209. Green, D. L. C.; Thompson, C. M. Tetrahedron Lett. 1991, 32, 5051.
210. Thompson, C. M. Heterocycles 1992, 34, 979.
211. Bravo, P.; De Vita, C.; Resnati, G. Gazz. Chim. Ital. 1987, 117, 165.
212. Weber, R. W.; Cook, J. M. Heterocycles 1982, 19, 2089.
213. Gleiter, R.; Merger, R. Tetrahedron Lett. 1989, 30, 7183;
214. Gleiter, R.; Merger, R. Tetrahedron Lett. 1990, 31, 1845.
215. Bates, R. B.; Cannon, F. A.; Kane, V. V.; Mishra, P. K.; Suvannachut, K.; White, J. J. J. Org. Chem. 1989, 54, 311.