Efficient and versatile synthesis of a-ring precursors of 1α, 25-dihydroxy-vitamin D 3 and analogues. Application to the synthesis of Lythgoe-Roche phosphine oxide
…, M Torneiro, C Vitale, S Fernández, J Pérez-Sestelo…
An efficient, versatile synthesis of Lythgoe-Phosphine Oxide has been developed starting from l-carvone. The key steps are rupture of protected epoxide 7 to give dicarbonyl compound 8, preparation of vinylic triflate 2, and palladium-catalysed cyclization- carbonylation of vinylic triflate 2.