Concise enantioselective synthesis of wine lactone via intramolecular Diels-Alder reaction.

An enantioselective synthesis of (3S,3aS,7aR)-wine lactone, a major aroma component of white wine and citrus juices, was achieved starting from (S)-2-methyl-3-butenoic acid. An intramolecular Diels-Alder reaction was employed as a key step.