ChemInform Abstract: Preparation of 3-Amino-4-(hydroxymethyl)azetidin-2-ones from the Reaction of Glycine Enolates with Imines of a Glycoaldehyde.

Abstract

β-Lactams with hydroxymethyl substitution at C-4 are formed in a single step in good yield by lithium ester enolate condensations of the glycoaldehyde-derived imine 14. Significantly, these reactions occur with minimal competing enolization of the glycoaldimine. Imine 14 is most conveniently generated in situ from the corresponding α-cyano secondary amines 8a, b. Asymmetric induction in forming the C-4 stereocenter of the β-lactam ring is excellent; however, condensations of the silyl glycinate enolate 1 with 14 afford preferentially β-lactams with the trans relationship of the amino and hydroxymethyl substituents