High asymmetic induction in a photo-Diels–Alder addition
Abstract
(S)-α-(2-Methoxymethyl-1-pyrrolidinyl)-acrylonitrile (S)-(1) and its (R)-enantiomer undergo efficient (2 + 4) photo-addition to electronically excited 1-acetylnaphthalene to form the adducts (+)- and (–)-(2); hydrolysis of the latter yields the chiral 1,4-diketones (–)- and (+)-(3) in 97% enantiomeric excess.