Highly Stereocontrolled Total Synthesis of (+)-Bengamide E.

Diisopropyl D-tartrate 7 was efficiently transformed into the hexacarbonyl dicobalt complexed aldehyde 23. A highly stereocontrolled aldol reaction of 23 with the O,S-acetal 20 in the presence of tin(IV) chloride provided, after decomplexation, the aldol adduct 21 as the sole product, which was subsequently converted into (+)-bengamide E 5.