A NOVEL ENTRY INTO CYCLOPRONATED SUGAR AMINO-ACIDS

Reaction of sugar triflates (1) and (2) with tert-butyl cyanoacetate i n presence of sodium hydride affords the cyclopropanated sugars (3) an d (4), followed by selective hydrolysis of the ester group to free aci ds (5) and (6), respectively. Couplings of (5) and (6) with protected glycine and L-alanine lead to cyclopropanated sugar amino acids (7-10) . The coupling of 6 with benzyl ethyl)methano-3,4-dideoxy-beta-L-arabi nopyranoside (11) furnished benzyl 3,4-[(C-cyano-amido)methano-(benzyl nopyranosido)]-3,4-dideoxy-beta-L-arbinopyranoside (12), suggesting a n ''exo'' orientation of the eater group in 3 and 4.