Radical species are postulated intermediates in the formation of the carbon-sulfur bonds of biotin. It was of interest to examine the behaviour of unsaturated analogues which should give rise to allylic radicals. The two isomers of 4,5-dehydrodethiobiotin have been synthesized and labelled with C-14 On their carboxylic acid group. When incubated with an in vitro system capable of transforming dethiobiotin into biotin, they covalently label biotin synthase. Copyright (C) 1996 Elsevier Science Ltd
Transition-metal catalyzed silylzincation and silylalumination of acetylenic compounds