14beta-Hydroxybaccatin III, a compound with limited availability by natural sources, is the starting material for the synthesis of the second-generation anticancer taxoid ortataxel. The 7-tertbutoxycarbonyl- (1a) and 7-triethylsilyl (1b) derivatives of 14beta-hydroxybaccatin III 1,14-carbonate were synthesized from 10-deacetylbaccatin III (3). The crucial steps were (a) the C(14)beta hydroxylation of the corresponding 13-oxobaccatin III derivatives by oxaziridine-mediated electrophilic oxidation and (b) the reduction of the C-13 carbonyl group with sodium or alkylammonium borohydrides. This protocol provides a practical way for the semisynthesis of ortataxel from 10-deacetylbaccatin III, a compound readily available from various yews.
Diastereoselective 14 beta-hydroxylation of baccatin III derivatives
Battaglia A;Guerrini A;
2003
Abstract
14beta-Hydroxybaccatin III, a compound with limited availability by natural sources, is the starting material for the synthesis of the second-generation anticancer taxoid ortataxel. The 7-tertbutoxycarbonyl- (1a) and 7-triethylsilyl (1b) derivatives of 14beta-hydroxybaccatin III 1,14-carbonate were synthesized from 10-deacetylbaccatin III (3). The crucial steps were (a) the C(14)beta hydroxylation of the corresponding 13-oxobaccatin III derivatives by oxaziridine-mediated electrophilic oxidation and (b) the reduction of the C-13 carbonyl group with sodium or alkylammonium borohydrides. This protocol provides a practical way for the semisynthesis of ortataxel from 10-deacetylbaccatin III, a compound readily available from various yews.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
