Two Convergent Approaches to the Synthesis of 1α,25-Dihydroxy-2β-(3-hydroxypropoxy)vitamin D3 (ED-71) by the Lythgoe and the Trost Coupling Reactions

Two convergent syntheses of 1α,25-dihydroxy-2β-(3-hydroxypropoxy)vitamin D 3 (ED-71) by the Lythgoe coupling reaction between the A-ring phosphine oxide and the C/D-ring ketone and the Trost coupling reaction between the A-ring ene-yne and the C/D-ring bromomethylene are described.