Taxol resulted from the tail addition of the Ojima lactam to alcohol 51, which is baccatin III (the original target molecule of the Danishefsky synthesis).  Alcohol 51 was derived from the allylic oxidation of α-acylketone 49.  Compound 49 was ultimately derived from the Heck reaction of enol triflate 38, which was used to close the B-ring.  Enol triflate 38 resulted from a rearrangement of compound 31 after protection of its hydroxyl group.  Compound 31 was derived from the connection of the A and C rings with aldehyde 21 combining with the vinyllithium reagent derived from cyanohydrin 29.  Cyanohydrin 29 originated as the ethyl isopropyl ketone (22).  Aldehyde 21 was obtained from compound 17, which was the product of the opening of ketal 12.  Ketal 12 was ultimately derived from the Wieland-Miescher ketone (1).