Additions of Group 6A and 7A Electrophilic Reagents to Dimethyl endo,endo-Bicyclooct-5-ene-2,3-dicarboxylate: Competitive Formation of γ- and δ-Lactones

Article abstract of DOI:10.1021/jo01293a016

The reaction of dimethyl endo,endo-bicyclo<2.2.2>oct-5-ene-2,3-dicarboxylate with chlorine, bromine, iodine, benzeneselenenyl chloride, and benzenesulphenyl chloride has been studied.Under conditions of kinetic control both γ- and δ-lactones are formed, the δ lactone being predominant except in the case of bromine.The thermodynamic product distributions favored the δ-lactone exclusively.A general mechanistic scheme is proposed.