Palladium-catalysed coupling of vinyl triflates with enynes and its application to the synthesis of 1α,25-dihydroxyvitamin D3

Article abstract of DOI:10.1016/S0040-4020(01)86410-3

We describe a general approach, based on the palladium-catalysed coupling of enynes with vinyl triflates, for the construction of dienynes related to vitamin D metabolites and analogues. As an application of this method, an efficient convergent synthesis of 1α,25-dihydroxyvitamin D₃ starting from the Inhoffen-Lythgoe diol (6a) and natural carvones has been carried out (11 steps, 28% overall yield from 6a). This strategy allows labelling of the side chain in the final steps of the synthesis.