The preparation of 4,5-dihydro-5-phenyl-5-(2-phenylethenyl)isoxazoles,4,5-dihydro-5-methyll-5-(2-phenylethenyl)isoxazoles,or 4,5-dihydro-5,5-di-(2-phenylethenyl)isoxazoles from dilithiated c(#alpha#),O-oximes and select #alpha#,#beta#-unsaturated ketones

摘要

C(#alpha#),O-oximes were dilithiated with lithium diispopropylamide and condensed with three #alpha#,#beta#-unsaturated ketones:(2E)-1,3-diphenyl-2-propen-1-one,or (1E,4E)-1,5-diphenyl-1,4-phentadien-3-one,or (3E)-4-phenyl-3-buten-2-one,followed by immediate acid cyclization to variously substituted 4,5-dihydroisoxazoles:4,5-dihydro-5-phenyl-5-(2-phenylethenyl)isoxazoles,4,5-dihydro-5-methyl-5-(2-phenylethenyl)isoxazoles,or 4,5-dihydro-5,5-di-(2-phenylethenyl)-isoxazoles.