反应详情

As noted above, the 3β-hydroxy-27-norcholest-5,7-dien-25-one prepared in accordance with the process of the instant invention is readily converted by techniques well-known in the art into 25-hydroxyvitamin D3. Thus, as described in the previously cited RECUEIL reference, 3β-hydroxy-27-norcholest-5,7-dien-25-one in dry benzene may be treated with methyl magnesium bromide at about 5° C. The reaction mixture is stirred for 8 - 18 hours and then is worked up by the addition of an aqueous solution of ammonium chloride. The cholest-5,7-diene-3β,25-diol so produced is crystallized from successively tetrahydrofuran-diisopropyl ether and tetrahydrofuran-ethyl acetate.

1. customprepared in accordance with the process of the instant invention