Synlett 2004(11): 1941-1944  
DOI: 10.1055/s-2004-830890
LETTER
© Georg Thieme Verlag Stuttgart · New York

An Approach to β-Substituted γ-Butyrolactones and its Application to the Synthesis of Lignans

Yuichi Isemori, Yuichi Kobayashi*
Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259-B52 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
Fax: +81(45)9245789; e-Mail: ykobayas@bio.titech.ac.jp;
Further Information

Publication History

Received 23 April 2004
Publication Date:
06 August 2004 (online)

Abstract

Copper-catalyzed reaction of 4-cyclopentene-1,3-diol monoacetate with ArCH2MgCl afforded 4-arylmethyl-2-cyclopenten-1-ols regioselectively. Subsequent cleavage of the cyclopentene ring followed by functional group manipulation provided the key β-arylmethyl-γ-butyrolactones for the synthesis of lignans. In addition, synthesis of the rolipram lactone intermediate was accomplished.

13

Attempted reactions of TBS ether 13 with acidic H5IO6 and of the triol with NaIO4 in place of KIO4 gave mixtures of products.

14

The observed specific rotation of the enterolactone dimethyl ether 15 in comparison with the reported values indicates no significant loss in enantiomeric purity at the carbon bearing the benzyl group during the ozonolysis and subsequent reduction of the intermediate (aldehyde).