Allocolchicinoid synthesis from colchicine

From the above literature studies, it seems clear that semi-synthesis has turned out to be the method of choice to generate a whole range of novel allocolchicinoid compounds from readily available colchicine precursors. Some of these synthetic allocolchicinoids have very potent antimitotic properties, and they have been used as tools to study tubulin-ligand interactions. The recent discovery of phosphate 35 as a prodrug with anti-... 

Contrary to most allocolchicinoids which lack a C-ll substituent, compounds 78 and 80 show stable axial chirality. The above study constitutes the first example in the allocolchicinoid series where both configurations at the biaryl axis can be obtained from a given stereochemistry at C-7. In the natural alio series, free rotation around the biaryl axis is often possible at room temperature, and the configuration of the biaryl axis is controlled by the stereochemistry at C-7 due to conformational constraints in the C-ring [14]. While several total enantioselective syntheses of colchicine address the control of the stereochemistry at C-7 [106], no direct enantioselective synthesis of natural allocolchicines has been reported to date. ... 

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