Totally synthetic analogues of siastatin B. II. Optically active piperidine derivatives having trifluoroacetamide and hydroxyacetamide groups at C-2.

Siastatin B analogues, optically active 2-(trifluoroacetamide)- 3,4,5-trihydroxypiperidines having nitromethyl, aminomethyl and carboxyl branched groups at C-5, and (+)-(2R,3R,4R,5R)-5-(aminomethyl)-3,4,5-trihydroxy-2- (hydroxyacetamido)piperidine have been obtained total synthetically from D-ribono-1,4-lactone. Some analogues have inhibitory activity against some glycosidases, and (+)-(2R,3R,4R,5R)-2-(trifluoroacetamido)-3,4,5-trihydroxypiperi dine-5-carboxylic acid showed a marked inhibitory activity against beta-glucuronidase.