A new procedure for the synthesis of C-glycosides of nojirimycin

Reaction with allylmagnesium bromide of N,2,3,4,6-pentabenzyl-D-glucopyranosylamine 2, obtained from tetrabenzylglucose and benzylamine, afforded stereoselectively the open chain amino alcohol 3, which was converted into the C-glycoside of nojirimycin 6 by full protection of the amino function by Fmoc, oxidation of the free hydroxy group, hydrolysis of the Fmoc group and final intramolecular reductive amination with NaBH(OAc)3; compound 6 was also converted into methyl ketone 7, by manipulation of the allylic appendage.