Novel Synthetic Strategy Towards Taxol by Macrocyclization Reaction – Conformational Requirement of Ring A

The synthesis of a completely substituted ring A of Taxol is reported and it is shown that the C-13-op group must have a beta configuration to succeed in the formation of 12-membered rings, a requisite for the construction of the B and C rings of Taxol by a macrocyclization step. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)