stereodefined propargylic or allylic alcohol side chain were transformed into the corresponding mesylates. Alkylation of these allylic mesylates by means of organocuprate reagents effected a regio and stereoselective 1,3-transfer of chirality. Similarly, alkylation of the propargylic mesylate gave a chiral allenyl oxazolidine. The N-Boc-2-alkenyl oxazolidines resulting from an anti SN2′ addition underwent an