Diastereoselective Diels–Alder cycloaddition of [(1R)-10-(N,N-diethylsulfamoyl)isobornyl] 2H-azirine to nucleophilic 1,4-disubstituted 1,3-dienes
作者:Maria J. Alves、Cátia Costa、Mário M. Durães
DOI:10.1016/j.tetasy.2009.05.035
日期:2009.7
Chiral [(IR)-10-(N,N-diethylsulfamoyl)isobornyl] 2H-azirine 1 [Timen, A.S.: Somfai, P.J. Org. Chem. 2003, 9958-9963; Timen, A. S.; Fisher, A.; Somfai, P. Chem. Commun. 2003, 1150-1151]. was combined to a number of 1,4-disubstituted-2-aza-1,3-dienes 2a-g (Alves, M. J.; Duraes, M. M.; Gil Fortes, A. Tetrahedron 2004, 6541-6553] to give cycloadducts 8a-g as major isomers. High to good diastereofacial differentiation of the two faces of the azirine is observed when R-1,R-2 = At 2a-e; diastereoselectivity drops drastically when R-1 = Me or H 2f,g. Cycloaddition of the azirine 1 to E,E-1,4-diacetoxy-1,3-butadiene shows complete diastereoselectivity giving cycloadduct 11a. (C) 2009 Elsevier Ltd. All rights reserved.