Total synthesis of (-)-denticulatins A and B using efficient methods of acyclic stereocontrol

Article abstract of DOI:10.1016/0040-4020(95)01015-7

The total synthesis of (-)-denticulatin B (2) was achieved in 9 steps (20% yield), with 70% overall diastereoselectivity, starting from the ethyl ketone (R)-9. Most of the stereochemistry was introduced by substrate-based control. Key steps include the boron-mediated aldol/reduction, 9 → 22, the titanium-mediated aldol-coupling. 26 + 8 → 38, and the directed cyclisation, 35 → 2. Epimerisation at C₁₀ in 35 led to (-)-denticulatin A (1).