Asymmetric synthesis of β-substituted α-methylenebutyro-lactones via trip-catalyzed allylation: Mechanistic studies and application to the synthesis of (S)-(-)-hydroxymatairesinol

Abstract

Asymmetric allylation of (hetero)aromatic aldehydes by a zinc(II)-allylbutyrolactone species catalyzed by a chiral BINOL-type phosphoric acid gave β-substituted α-methylenebutyrolactones in 68 to >99% ee and 52-91% isolated yield. DFT studies on the intermediate Zn 2+-complex - crucial for chiral induction - suggest a six-membered ring intermediate, which allows the phosphoric acid moiety to activate the aldehyde. The methodology was applied to the synthesis of the antitumour natural product (S)-(-)-hydroxymatairesinol. © 2013 The Authors. Published by Wiley-VCH Verlag GmbH &Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.