5-Trihydroxypropyl-dihydrouracil derivatives as precursors of 1-azasugars: application to the stereoselective synthesis of D-galacto-isofagomine

A new route for the synthesis of isofagomine analogues has been carried out by using as precursors enan- tiopure 5-trihydroxypropyl-dihydrouracil derivatives obtained from aldol-type addition of 1,3-dibenzyl- dihydrouracil to isopropylidene-protected glyceraldehyde. The synthesis of D-galacto-isofagomine is reported.