Colchinol analogue

In the course of their synthesis of colchicine [102], Banwell and coworkers found that the tricyclic intermediate 74, Fig. (15), aromatized in the presence of //-toluenesulfonic acid to give the colchinol analogue 75 [103]. The methyl ester 76 and the previously described methyl ether 72 obtained from 75 were found to be potent inhibitors of tubulin polymerization. 

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