Enantio- and diastereodifferentiating cis,trans-photoisomerization of 2β,3β-diphenylcyclopropane-1α-carboxylic acid derivatives in organized media

Organic Letters

Volumn 2, Issue 18, 2000, Pages 2801-2804

  Cheung, Eugene ^a   Chong, Kenneth C W ^a   Jayaraman, Sivaguru ^b   Ramamurthy, V ^b   Scheffer, John R ^a   Trotter, James ^a  

^a UNIVERSITY OF BRITISH COLUMBIA   (Canada)

^b Tulane University   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000138463     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol0062190     Document Type: Article

References (17)

1. (a) Hammond, G. S.; Cole, R. S. J. Am. Chem. Soc. 1965, 87, 3256.
2. (b) Aratani, T.; Nakanisi, Y.; Nozaki, H. Tetrahedron 1970, 26, 1675.
3. Ouannès, C.; Beugelmans, R.; Roussi, G. J. Am. Chem. Soc. 1973, 95, 8472.
4. Ueno, A.; Toda, F.; Iwakura, Y. J. Polym. Sci., Polym. Chem. Ed. 1974, 12, 1841.
5. Faljoni, A.; Zinner, K.; Weiss, R. G. Tetrahedron Lett. 1974, 1127.
6. Inoue, Y.; Yamasaki, N.; Shimoyama, H.; Tai, A. J. Org. Chem. 1993, 58, 1785.
7. Blatchford, J. K.; Orchin, M. J. Org. Chem. 1964, 29, 839.
8. Absolute asymmetric synthesis refers to the formation of enantiomerically enriched products from achiral precursors without the intervention of a preexisting source of optical activity. For a discussion, see: Caswell, L.; Garcia-Garibay, M. A.; Scheffer, J. R.; Trotter, J. J. Chem. Educ. 1993 70, 785.
9. The unknown photoproduct was initially assigned the structure methyl 3,4:5,6-dibenzo-1,3,5-cycloheptatriene-1-carboxylate, but independent synthesis of this material by the method of Ford and Newcomb (Ford, W. T.; Newcomb, M. J. Am. Chem. Soc. 1973, 95, 6277) did not give a match. Efforts are ongoing to establish the structure of this compound.
10. Ester 1b: Pbca; a = 17.648(5) Å, b = 16.540(5) Å, c = 9.679(5) Å; α = β= γ = 90°; Z = 8; R = 5.1%.
11. (a) Joy, A.; Uppili, S.; Netherton, M. R.; Scheffer, J. R.; Ramamurthy, V. J. Am. Chem. Soc. 2000, 122, 728.
12. (b) Joy, A.; Scheffer, J. R.; Ramamurthy, V. Org. Lett. 2000, 2, 119.
13. (c) Joy, A.; Ramamurthy, V. Chem. Eur. J. 2000, 6, 1287.
14. -3 Torr) at 65 °C for 8-12 h and transferred to a quartz tube inside a drybox. Freshly distilled anhydrous hexane was added, the tube sealed, and the resulting slurry irradiated for 1 h (30-40% conversion) using the unfiltered output of a 450 W hanovia medium-pressure mercury lamp. The de was found to be independent of the extent of conversion. After photolysis, the zeolite was filtered, washed again with fresh hexane, and then stirred with acetonitrile for 6-8 h to extract the product(s). The extracts were then concentrated and analyzed using capillary gas chromatography. The extent of de depends on the dryness of the zeolite. For example, in the case of the 1-phenylethyl amide of 1a, wet LiY gave an 8% de of peak 1, whereas dry LiY zeolite afforded peak 2 in 80% de.
15. The ratio of the two enantiomers in peak 2 was not determined.
16. Gamlin, J. N.; Jones, R.; Leibovitch, M.; Patrick, B.; Scheffer, J. R.; Trotter, J. Acc. Chem. Res. 1996, 29, 203.
17. The amines used were (R)-(+)-1-phenylethylamine, (S)-(-)-1-p-tolylethylamine, (S)-(-)-1-p-bromophenylethylamine, (R)-(+)-1-p-chlorophenylethylamine, L-proline, (S)-(-)-α,α-diphenyl-2-pyrrolidinemethanol, (R)-(+)-N-benzyl-1-phenylethylamine, (S)-(-)-2-(diphenylmethyl)pyrrolidine, (S)-(+)-2-methoxymethylpyrrolidine, and (R)-(-)-2-methyl-2-phenylethylamine.