An asymmetric Diels-Alder reaction with a diene bearing a chiral sulfinyl group is described. The Lewis acid-catalyzed intramolecular asymmetric hetero Diels-Alder reaction of a chiral α'-sulfinyl-α, β-unsaturated ketone derived from 3-methylcitronellal produced optically active 4a, 5, 6, 7, 8, 8a-hexahydro-1H-2-benzopyran derivatives. On the basis of the stereochemical results obtained, a plausible mechanism for the asymmetric induction is presented.