Synthesis of the enantiomers of 6-epicastanospermine and 1,6-diepicastanospermine from D- and L-gulonolactone.

The synthesis of the enantiomers of 6-epicastanospermine and of 1,6-diepicastanospermine from the enantiomeric gulonolactones is reported and the structure of the former is established as (1S,6R,7R,8R,8aR)-1,6,7,8-tetrahydroxyoctahydroindolizine. The inhibitory activities of the diastereomers against the amyloglucosidase-catalysed hydrolysis of p-nitrophenyl alpha-D-glucopyranoside were investigated, and the effects of 6-epicastanospermine and of 1,6-diepicastanospermine on 14 human liver glycosidases are reported.