Highly Stereo- and Regioselective Formation of 2-Oxazolone Telomers, Potential Synthetic Intermediates for Amino Sugars

Article abstract of DOI:10.1021/jo00143a024

Free radical initiated reaction of 3-acyl-2-oxazolones proceeds smoothly in polyhalomethanes, which function as telogens, to give type 3 telomers of synthetic potential with high regio- and stereoselectivity, while the 3-alkyl derivatives failed to give such polyfunctional products.This particular telomerization can be controlled exclusively in the trans ''head-to-tail'' addition mode, as elucidated by 1H and 13C NMR and X-ray analysis of the products.Thus, the 3-benzoyl heterocycle 7 gave trans-4-chloro-5-(trichloromethyl)-2-oxazolidone (8) as a sole 1:1 adduct andtwo trans isomers of 4'-chloro-5-(trichloromethyl)<4,5'-bioxazolidinyl>-2,2'-dione (9a,b) as 2:1 telomers.Some characteristic reactions of the telomers are described.