Patent ID: 6384071
Filing Date: 2002-05-07
Classification: C07D

Abstract:
A process for preparing a compound of formula III: in which Ar represents an aryl radical,R1 represents a benzoyl radical or a radical R2â€”Oâ€”CO in which R2 REPRESENTS an alkyl, alkenyl, alkynyl, cycloalkenyl, bicycloalkyl, phenyl, or heterocyclic radical; and G1 represents a hydrogen atom or an acetyl, alkoxyacetyl or alkyl radical, or other hydroxy-protecting group; comprisinga) treating in an acidic medium a compound of formula II, in which Ar represents an aryl radical;R1 represents a benzoyl radical or a radical R2â€”Oâ€”CO in which R2 represents an alkyl, alkenyl, alkynyl, cycloalkyl, cyclokenyl, bicycloalkyl, phenyl or heterocyclyl radical; R3 and R4, which are identical or different, each independently represent a hydrogen atom, or an alkyl radical containing 1 to 4 carbon atoms, or an aralkyl radical in which the alkyl portion contains 1 to 4 carbon atoms and the aryl portion is unsubstituted or substituted by one or more alkoxy radicals containing 1 to 4 carbon atoms, or an aryl radical unsubstituted or substituted by one or more alkoxy radicals containing 1 to 4 carbon atoms; or R3 represents an alkoxy radical containing 1 to 4 carbon atoms or a trihalomethyl radical or a phenyl radical substituted by a trihalomethyl radical and R4 represents a hydrogen atom; or R3 and R4 form, together with the carbon atom to which they are bound, a cyclic radical with 4 to 7 members; and G1 represents a hydrogen atom or an acetyl, alkoxyacetyl or alkyl radical, or other hydroxy-protecting group; to yield the compound of formula III.