Piperonal as electrophile in the Baylis-Hillman reaction.: A synthesis of hydroxy-β-piperonyl-γ-butyrolactone derivative

Aromatic aldehydes are reluctant to serve as substrates for the Baylis-Hillman reaction at all under the relatively mild conditions. In our research, we have achieved that piperonal could be an useful substrate in this reaction, employing ultrasound technique. The adduct obtained was used in the preparation of key intermediates for the total synthesis of hydroxylated lignans. (C) 1998 Elsevier Science Ltd. All rights reserved.