NEW MATERIAL: A compound represented by formula I [wherein X is formula II, formula III (wherein R2 is H, an acyl, an alkylsilyl or tetrapyranyl) or the like; and R1 is R2].
USE: A material for the production of an active vitamin D3 derivative 25- hydroxyvitamin D3-26,23-lactone.
PREPARATION: For example, a 24-nor-5-cholen-23-oic acid represented by formula IV is reduced into a 23-alcohol, this alcohol is oxidized into a 23-aldehyde derivative, and this derivatives is subjected to an aldol condensation together with acetone or an acetone equivalent in the presence of a catalyst and a solvent to form a hydroxy-ketone derivative represented by formula V. The resultant compound is optionally treated with a cyanide and then converted into a hydroxy-acid, and this is hydrolyzed and treated with e.g. hydrochloric acid to obtain a lactone derivative represented by formula VI.
HAINRITSUHI KEE SHIYUNOOZU
HAABAATO II PAREN
JIYOSEFU KEE UITSUKUMAN
MEARII EI FUIBITSUTSUANI
