Synthesis of aziridine-2-carboxylates via conjugate addition of an amine to 2-(5H)-furanon-3-yl methanesulfonate: application to the preparation of α-amino-β-hydroxy-γ-butyrolactone

Conjugate addition of benzylamine to 2-(5H)-furanon-3-yl methanesulfonate in methanol afforded a 7:1 mixture of the trans and cis methyl N-benzyl-2-hydroxymethylaziridine-2-carboxylates 7 and 8, respectively. Treatment of 7 with benzyl alcohol in the presence of BF3·OEt2 then furnished, after hydrogenolysis, rac–cis α-amino-β-hydroxy-γ-butyrolactone (1).