Variable strategy toward carbasugars and relatives as illustrated by diastereoselective synthesis of 1-deoxy-1-amino-pseudo-beta-D-gulopyranose (alias 1,2,4-tri-epi-validamine)

[GRAPHICS] A quick arrival at chiral nonracemic cyclohexanoids is provided, which inco rporates useful variability for large product diversity. Central to the con struction is the exploitation of the dual nucleophilic character of an easi ly accessible triad of silyloxy diene synthons derived from the popular fiv e-membered heterocycles furan, pyrrole, and thiophene. To assess the reliab ility of the procedure, the total synthesis of 1-deoxyl-1-amino-pseudo-ss-D -gulopyranose (10) (alias 1,2,4-tri-epi-validamine) is executed, in 12 step s and with a 17% overall yield, by starting with N-tert-butoxycarbonyl-2-[( tert-butyldimethylsilyl)oxy]pyrrole (1) and 2,3-O-isopropylidene-D-glyceral dehyde (2).