Patent ID: 6878834

Claim:
A tetracyclic taxane having the formula wherein R 2 is hydrogen, hydroxy, or —OCOR 31 ; R 4a is hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, cyano, hydroxy, or —OCOR 30 ; R 7a is hydrogen, halogen or —OR 28 ; R 10a is hydrogen, —OCOR 29 , hydroxy or protected hydroxy; R 13 is hydroxy or protected hydroxy; R 14 is hydrogen; R 28 is hydrogen, acyl, or hydroxy protecting group; and R 29 , R 30 and R 31 are independently hydrogen, alkyl, alkenyl, alkynyl, monocyclic aryl or monocyclic heteroaryl.