| 摘要 |
A process comprising the step of alkylating the hydroxyl functions at the 7-position and 10-position of a compound of formula (V); A represents hydrogen, a side chain of formula (Ic), or an oxazolidine of formula (Id); G represents a hydroxyl protecting group; R1 represents: alkyl, alkenyl, alkynyl, cycloalkyl, phenyl or á or â -naphthyl, optionally substituted with one or more atoms or radicals, an optionally substituted 5-membered aromatic heterocycle containing one or more hetero atoms, which may be identical or different, chosen from nitrogen, oxygen or sulphur atoms, R1 is a substituted phenyl radical, a substituted á- or â-naphthyl radical, or a substituted aromatic heterocycle; R2 represents: a benzoyl radical, optionally substituted with one or more atoms or radicals, which may be identical or different, a radical R'2 --C--CO--, wherein R'2 represents: Alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl or a bicycloalkyl, these radicals being optionally substituted with one or more substituents, a phenyl or á or â-naphthyl radical, optionally substituted with one or more atoms or radicals, an optionally substituted saturated heterocyclic radical; R3 and R4 which may be identical or different, represent: Hydrogen, alkyl, aryl, halo, alkoxy, arylalkyl, alkoxyaryl, haloalkyl or haloaryl, or R3 and R4 together form a 4- to 7-membered ring; alkylation is carried out in the presence of: (i) an alkylating agent, wherein the alkylating agent is an alkyl halide, an alkyl sulphate, or an oxonium; and (ii) an anionization agent. |
