Conversion of 9-dihydro-13-acetylbaccatin III to baccatin III and 10-deacetyl baccatin III
OwnerGertrude C. Kasitu, Japheth W. Noahinventors
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Abstract
Novel methods and synthetic intermediates to prepare baccatin III and 10-deacetylbaccatin from readily available 9-dihydro-13-acetylbaccatin III are described. Selective protection and deprotection of the C-7 hydroxyl functionality provides an entry into facile synthesis of novel taxol intermediates, as well as, providing new methods for the preparation of paclitaxel and docetaxel in large scale. Selective oxidation of the C-9 hydroxyl without the need for protection of the C-7 hydroxyl is described.
Claims17
A compound having the formula
- 14
- wherein R is a polymeric protecting group or an acetate group.
A compound having the formula
- 15
- wherein R is a polymeric protecting group or an acetate group.
A compound having the formula
- 16
A compound having the formula
- 17
A method for the preparation of baccatin III, comprising the steps of:
- a) selectively protecting the C-7 hydroxyl group of 9-dihydro-13-acetylbaccatin III as either an acetate group or with a polymeric protecting resin;
- b) selectively oxidizing the C-9 hydroxyl group with an oxidizing agent;
- and
- c) selectively deprotecting the protected C-7 hydroxyl group after oxidation to provide baccatin III.
A method for the preparation of 10-deacetylbaccatin III, comprising the steps of:
- d) selectively protecting the C-7 hydroxyl group of 9-dihydro-13-acetylbaccatin III as an acetate group or with a polymeric protecting resin;
- e) selectively oxidizing the C-9 hydroxyl group with an oxidizing agent;
- and
- f) selectively deprotecting the protected C-7 hydroxyl and C-10 hydroxyl groups after oxidation to provide 10-deacetylbaccatin III.
A method for the preparation of the compound having the formula
- 18
- from 9-dihydro-13-acetylbaccatin III, comprising the step of:
- treating 9-dihydro-13-acetylbaccatin III with an oxidizing agent such that only the C-9 hydroxyl group of 9-dihydro-13-acetylbaccatin III is oxidized to the corresponding ketone.
Dependencies are inferred from the claim text.