Regioselectivity in the ring opening of 2-phenyl-1,3-dioxan-2-yl radicals derived from cyclic benzylidene acetals and comparison with deoxygenation of a carbohydrate diol via its cyclic thionocarbonate
作者:Brian P Roberts、Teika M Smits
DOI:10.1016/s0040-4039(01)00540-8
日期:2001.5
Ring-opening β-scission of monocyclic 2-phenyl-1,3-dioxan-2-yl radicals gives preferentially the more stabilised alkyl radical. However, analogous bicyclic radicalsderived from two 4,6-O-benzylidene glucopyranosides afford primary radicals in preference to secondary radicals, a result that can be rationalised with the aid of DFT calculations. The report by Barton and Subramanian, that the opposite