Preparation of taxoid compounds (I) comprises reacting an optionally protected taxene compound (II) with a molecular sieve base in sulfolane, condensing with a side chain, and removing protecting groups. Preparation of taxoid compounds of formula (I) comprises reacting an optionally protected taxene compound of formula (II) with a basic molecular sieve in sulfolane to cyclize the 7 beta -trifluoromethyl sulfonyloxy group, condensing with a side chain, and removing protecting groups. [Image] Ar : aryl； R : H, acetyl, alkoxyacetyl or alkyl； R 1benzoyl or R 2-O-CO； R 21-8C alkyl； R' : a protecting group when R in (I) is H, or R. An independent claim is also included for the preparation of intermediate compounds of formula (III) which comprises reacting (II) with a molecular sieve base in sulfolane. [Image] ACTIVITY : None given. MECHANISM OF ACTION : None given.從4-乙醯氧基-2 α-苄醯氧基-5β,20-環氧基-1,13 α-二羥基-9-酮基-7β-(三氟甲加磺基氧基)紫杉-11-烯與分子篩在碸茂烷中反應，製備4-乙醯氧基-2 α-苄醯氧基-5β,20-環氧基-1,13 α-二羥基-9-酮基-19-去環丙[g]紫杉-11-烯。
