Synthesis of New Biotin Derivatives

It is now established that the formation of C–S bonds during the conversion of dethiobiotin into biotin involves intermediate carbon radicals. To examine the behavior of dethiobiotin analogs that could lead to allylic and α-epoxyradicals, we have synthesized 4,5-dehydrodethiobiotins and the corresponding epoxides and 5,6-dehydrodethiobiotins. All these compounds have been labelled with 14C on the carboxyl group.