Butyl paclitaxel analog

Ali et al. reported " the synthesis of a series of C3 -f-butyl paclitaxel analogs with C3 -N amides and carbamates, among which A-debenzoyl-A-(2-thienoyl) analog 12 was the most potent. Although equipotent to docetaxel, and about 25 times more water soluble than paclitaxel, this taxane was not superior to analog 13 reported earlier. 

Ali SM, Hoemann MZ, Aube J, Mitscher LA, Georg GI (1995) Novel Cytotoxic 3 -(tert-Butyl) 3 -Dephenyl Analogs of Paclitaxel and Docetaxel. J Med Chem 38 3821... 

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