Back to results
US 5,508,447 AGranted
Short synthetic route to taxol and taxol derivatives
AssigneeBoard of Regents, The University of Texas System
InventorPhilip D. Magnus
Life of this patent
Estimating the term…
Abstract
A short route to the total synthesis of the core skeleton of the taxol ring system is described. The same sequence of transformations can be carried out to make the 7-hydroxy series, and connect the additional carbon atoms required for the A-ring. The number of steps to the taxane skeleton is 13, making it the shortest route from readily available inexpensive starting materials.
Claims1
A method of synthesis of the A/B/C ring system of taxol having the structure I where X is H or OH and R, R.sub.1 and R.sub.2 are independently H or lower alkyl, comprising the steps;
- ##STR16## (a) reacting compound II by gem-alkyl cyclopropanation of the activated enone where EWG is a cyano, ester or aldehyde group, PG is an O-protecting group and R is H or lower alkyl;
- ##STR17## (b) to form the adduct III where R.sub.1 and R.sub.2 are independently H or lower alkyl;
- ##STR18## (c) cleaving the internal cyclopropane C-C bond of III under reducing conditions to form IV;
- ##STR19## (d) adding a vinyl group to IV to form V;
- and ##STR20## (e) treating V under acidic conditions to ring close and removing the O-protecting group to form I.
2 more elements
Dependencies are inferred from the claim text.