Synthesis of 1,4-dideoxy-1,4-imino-derivatives of d-allitol, l-allitol and d-talitol: a stereo selective approach for azasugars

A stereo selective approach for the azasugars 1,4-dideoxy-1,4-imino-d-allitol, l-allitol, and 1,4-dideoxy-1,4-imino-d-talitol is described for different olefin compounds I derived from (R)-2,3-O-isopropylidine glyceraldehyde, l-ascorbic acid, and d-isoascorbic acid by using vinyl Grignard addition, allylation, RCM, and dihydroxylation as the key steps.