| abstract |
The present invention relates to a novel process for the preparation of bile esters derivatives of general formula (I), in which R0 is H or OH; R1 is H, α-OH or β-OH; R2 and R3 are independently hydrogen, straight or branched (C1-C20) alkyl optionally substituted with aryl; R5 is a straight or branched (C1-C4) alkyl and R6 is a straight or branched (C1-C4) alkyl or a benzyl group, via transamidation of the amine (V) with the 5-ocoproline derivative (II), wherein R4 is selected from the group consisting of tertbutoxycarbonyl, methoxycarbonyl, ethoxycarbonyl, 2-trimethylsilylethoxycarbonyl, cyclobutoxycarbonyl and 1-methylcyclobutoxy carbonyl, followed by the selective cleavage of the protecting group R4 under acidic conditions. |