Synthesis of two osteoclast-forming suppressors, demethylincisterol A3 and chaxine A
摘要:
The synthesis of two potent osteoclast-forming suppressing agents isolated from the Chinese mushroom Agrocybe chaxingu, demethylincisterol A(3) and chaxine A. was accomplished using ergocalciferol as the starting material. Our methodology for the synthesis of demethylincisterol A(3) and chaxine A featured the construction of a butenolide moiety by the intramolecular Horner-Wadsworth-Emmons reaction under Masamune-Roush conditions. This is the first reported synthesis of chaxine A. (C) 2011 Elsevier Ltd. All rights reserved.
Chaxine B and itsanalogues were synthesized from ergosterol in eight steps on the basis of our proposed biosynthetic pathway, which includes a highly site-selective and regioselective Baeyer–Villiger oxidation as the key step. This synthesis enabled the revision of the structures of chaxine B and itsanalogues.