Facile synthesis of fused furanosyl β-amino acids from protected sugar lactones:: incorporation into a peptide chain

The synthesis of fused furanosyl beta-amino esters from protected sugar lactones is described, using the combination of a Wittig type reaction and 1,4-addition of benzylamine on the resulting glycosylidenes. This sequence of reactions afford either N-glycosyl-3-ulosonic acid esters, which are the beta-analogues of anomeric sugar alpha-amino esters, or open-chain sugar beta-enamino esters, when a retro-Michael reaction takes place after addition of benzylamine. Incorporation of the fused furanosyl beta-amino ester 2a into a peptide chain is also described. (C) 2002 Elsevier Science Ltd. All rights reserved.