Nitro-polyols via Pyridine Promoted C=C Cleavage of 2-Nitroglycals. Application to the Synthesis of (-)-Hyacinthacine A1

A mild and convenient transformation for the synthesis of nitro-polyols is described. The nitro-polyol derivatives were prepared either from 2-nitroglycals via a pyridine-promoted scission of the carbon-carbon double bond or from glycals via a sequential nitration-scission procedure. The generated nitro-polyols could undergo a stereoselective Michael addition reaction. The utility of the addition products was exemplified by the concise synthesis of (-)-hyacinthacine A1 and 7a-epi-(-)-hyacinthacine A1.