Acetic acid, 2-(triphenylphosphoranylidene)-, methyl ester → Triphenylphosphine Oxide

Participants

Reaction Steps

A solution of 64.8 g of (0.149) of 3α,12α-dihydroxy-24-cholanal, diformate and 55 g (10% excess) of carbomethoxymethylene triphenylphosphorane 12 in 250 ml of dry benzene was refluxed for 6 hr. The solvent was then removed under reduced pressure and the residue treated with 400 ml of a 3:1 solution of hexane-ether. The resulting precipitate was filtered to give 39 g of crude triphenylphosphine oxide. The filtrate was concentrated, dissolved in a minimum of benzene and washed through 600 g of silica gel with a 2% ethyl acetate-benzene solution. The solvent was removed and the residue crystallized from hexane to give 49 g of 5-(3α,12α-diformyloxy-5β-pregnane-20-yl)-trans-2-pentenoic acid methyl ester mp 112°-115°.

Provenance & Evidence