(E)-stereoselective synthesis of vinylglycines from (R)-serine via organocopper–BF3 and related reagents

Abstract

The stereoselective synthesis of biologically important vinylglycine derivatives by reaction of homochiral 4-methoxycarbonyl-5-vinyloxazolidin-2-ones with organocopper reagents is described; 4,5-trans-oxazolidin-2-one 6 yields (E)-vinylglycines as the major products by treatment with the ‘higher order’ cyanocuprate–BF₃ reagents or trialkylzincates in the presence of cuprous cyanide, 4,5-cis-oxazolidin-2-one 10 affords only the desired (E)-vinylglycines.