Isolation of α,α-difluoroketene silyl acetal and its application to asymmetric aldol reactions
摘要:
Salt-free alpha,alpha-difluoroketene silyl acetal 1 was prepared in pure form. Aldol reactions of 1 with aldehydes catalyzed by catalytic amounts of chiral Lewis acids 2 and 3 proceeded with excellent enantiomeric excess to give optically active alpha,alpha-difluoro-beta-hydroxy esters 4-11 (up to 98% ee). (C) 1997 Elsevier Science Ltd.
Salt-free alpha,alpha-difluoroketene silyl acetal 1 was prepared in pure form. Aldol reactions of 1 with aldehydes catalyzed by catalytic amounts of chiral Lewis acids 2 and 3 proceeded with excellent enantiomeric excess to give optically active alpha,alpha-difluoro-beta-hydroxy esters 4-11 (up to 98% ee). (C) 1997 Elsevier Science Ltd.