Asymmetric Diels-Alder Reaction with use of (S)-5-(Trityloxymethyl)pyrrolidin-2-one as a Chiral Auxiliary
(S)-5-(Trityloxymethyl)pyrrolidin-2-one (1) is an efficient and recyclable chiral auxiliary in the asymmetric Diels-Alder reaction of the imide (2) with dienes, affording cycloadducts (3) with excellent diastereofacial selectivity.