161759-86-0Relevant articles and documents
Asymmetric Synthesis of the Taxol and Taxotere C-13 Side Chains
Bunnage, Mark E.,Davies, Stephen G.,Goodwin, Christopher J.
, p. 2385 - 2392 (2007/10/02)
A practical and efficient asymmetric synthesis of the 3-benzoylamino-2-hydroxy-3-phenylpropionic acid derived side chain of the important anticancer agent taxol is described.The pivotal synthetic transformation relies upon the highly diastereoselective tandem lithium amide conjugate addition-electrophilic hydroxylation of tert-butyl cinnamate 4.The resultant anti β-amino-α-hydroxy acid derivative is readily converted to the anti diastereomer of the taxol side chain methyl ester, from which the naturally occuring syn configuration is secured by a simple Mitsunobu inversion sequence via a dihydrooxazole intermediate.Under optimal conditions, this straightforward approach provides the taxol side chain methyl ester (-)-15 (natural enantiomer) in four steps and 60percent yield from tert-butyl cinnamate 4.The protocol is applied to the preparation of all four taxol side chain stereoisomers and is extended to allow for the synthesis of the side chain of taxotere, a potent taxol analogue.