In the final synthetic steps (scheme 8) the amide tail 62 was added to ABCD ring 52 in an esterification catalysed by o,o'-di(2-pyridyl) thiocarbonate (DPTC) and DMAP forming ester 63. The Bn protecting group was removed by hydrogenation using palladium hydroxide on carbon (64) and finally the TES group was removed by HF and pyridine to yield Taxol 65.