Reduction of the triple bond of compound (I) with LiAlH4 in the presence of NaOMe furnished the E-olefin (II). The secondary alcohol group of (II) was then oxidized to the corresponding ketone (III) by means of pyridinium dichromate in the presence of pyridinium p-toluenesulfonate. Condensation of this ketone with the ylide resulting from phosphine oxide (IV) and n-BuLi produced the silylated cholecalciferol analogue (V). The silyl protecting groups of (V) were finally removed by treatment with tetrabutylammonium fluoride.