α, β-unsaturated esters and α-alkylidene lactones bearing one γ-hydrogen on the unsaturated chain, were deconjugated by irradiation with UV light (λ= 254 nm). When the reaction was carried out in the presence of (+) or (−) ephedrine, an enantioselective C- protonation of the photodienolic intermediate led to the deconjugated ester with an enantiomeric excess up to 30%. The scope of the reaction and the configuration of the ...
