From farnesol and (R)-methyloxirane the optically active bicyclic compounds 31 and 32 have been prepared. Cyclization of 31 led to the tricyclic compounds 29 and 30, respectively, which differ configurationally from forskolin only at C-8.
The complete synthesis of D-α-tocopherol was achieved using our developed-Ullmann C-O coupling reaction as a key reaction. The synthesis of the core structure of D-α-tocopherol, which is a chiral chromane, has never been reported using intramolecular Ullmann C-O coupling reactions owing to the low reactivity of electron-rich iodoarenes with tertiary alcohols. Because the developed intramolecular C-O
The thioacetate approach to vitamin D analogues. Part 2: Synthesis of (25S)-23-thia-1α,25,26-trihydroxyvitamin D3
作者:Zoila Gándara、Ousmane Diouf、Generosa Gómez、Yagamare Fall
DOI:10.1016/j.tetlet.2007.07.086
日期:2007.9
(25S)-23-Thia-1α,25,26-trihydroxyvitamin D3 (4) was prepared from alcohol 5 in 56% overall yield (five steps) using our previously developed methodology. Alcohol 5 was synthesized from commercially available vitamin D2.