The first synthesis of (S)-(+)-cacalol (1) was achieved by a combination of the BF 3 .Et 2 O-mediated reaction of (S)-4,5-epoxy-(2E)-pentenoate (7) with 3,4-dimethoxytoluene to give (S)-4-aryl-5-hydroxy-(2E)-pentenoate (5) and consecutive conversion of (S)-5 into (S)-1.