Selective protection of the C(7) and C(10) hydroxyl groups in 10-deacetyl baccatin III
摘要:
New protocols for the selective protection of the C(7) and C(10) hydroxyl groups of 10-deacetyl baccatin III are described, leading to more efficient semisyntheses of taxol and taxol analogs. The C(10) hydroxyl group of 10-DAB can be highly selectively acylated or silylated, and subsequent selective protection of the C(7) hydroxyl group then becomes straightforward. (C) 1998 Elsevier Science Ltd. All rights reserved.
CEPHALOMANNINE DERIVATIVES, THEIR PREPARATION, PHARMACEUTICAL COMPOSITION AND USE THEREOF
申请人:Fang Weishuo
公开号:US20110039921A1
公开(公告)日:2011-02-17
The present invention discloses cephalomannine derivatives of general formula (I), a process for preparation of such cephalomannine derivatives, a composition containing such compounds, and use of said compounds in the manufacture of a medicament for the treatment of tumors, especially multidrug resistant tumors.
A process is described for converting the C(7) hydroxy group of a 10-acyloxy-7-hydroxytaxane to an acetal or ketal, the process comprising treating the 10-acyloxy-7-hydroxytaxane with a ketalizing agent in the presence of an acid catalyst to form a C(7) ketalized taxane of the formula
or
wherein either X31 or X32 represents the 10-acyloxy-7-hydroxytaxane moiety and the other of X31 and X32 as well as X33 and X34 are independently hydrocarbyl, substituted hydrocarbyl or heteroaryl moieties. Taxanes having a ketalized C(7) hydroxy group are also described.