Taxol Heck reaction

Construction of the B ring of the congested taxol molecule 101 has been carried out by the intramolecular Heck reaction of the enol triflate 100 [46],... 

Z-tamoxifen 403 tandem cyclization 290, 295 tandem Heck reaction-anion capture 253-4 tandem Heck reaction-phenoxide capture 253 tandem Heck reactions 251, 252-4 tandem intramolecular Heck-intermolecular Stille cross-coupling 255 taxol 140, 143,243,245 ( )-tazettine 146,234 telomerization 352 telomerization products 343, 345 template effect 140 teraconic anhydride 468 terminal acetylenes, synthesis of 216-20 terminal alkynes 6, 213 terminal 2,2-diorgano-l-aIkcnylboronates 51 terminal diynes 207 ternary complex 444 ternary coupling 177... 

Scheme 3-52 A total synthesis of taxol employing the Heck reaction in a key step [162],...

In their studies toward the total synthesis of Taxol , Danishefsky and co-workers have focused their attention on the formation of eight-membered rings by an intramolecular Heck reaction proceeding by an -exo-trig cyclization of a 2-halo-1,8-decadiene system (Scheme 19, Table 14). 

Mizoroki-Heck cyclization of 198 was part of the studies towards the total synthesis of taxol (224) (see Scheme 5.38) by Danishefsky and coworkers [84] (198 199, Scheme 5.35). The strained seven-membered ring is formed in the presence of the hydroxyketone moiety in 52% yield and unconsumed 198 was re-isolated quantitatively. Danishefsky and coworkers [85] employed the high-yielding Mizoroki-Heck reaction of200 to assemble the bridged carbon skeleton in 201, an intermediate en route to the synthesis of CP-225,917 (202) and related CP-263,114 (not shown), which are squalene synthetase and famesyl transferase inhibitors (200 201). 

Two Heck reactions, the first intramolecular in an exo- sense, the second intermolecular, were used to prepare an intermediate 5.105 for a prostaglandin receptor antagonist on a 2.17 kg scale (Scheme 5.32). An intramolecular Heck reaction of a vinyl triflate 5.106 with an cxo-ring closure was employed to form an eight-membered ring in a synthesis of taxol (Scheme 5.33). ... 

Masters, J.J., Jung, D.K., Bornmann, W.G. and Danishefsky, S.J. (1993) A concise synthesis of a highly functionalized C-aryl taxol analog by an intramolecular Heck oleflnation reaction. 

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