Synlett 2008(11): 1643-1646  
DOI: 10.1055/s-2008-1078487
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Short Total Synthesis for Biologically Interesting (+)- and (-)-Machaeriol A

Likai Xia, Yong Rok Lee*
School of Chemical Engineering and Technology, Yeungnam University, Gyeongsan 712-749, Korea
Fax: +82(53)8104631; e-Mail: yrlee@ynu.ac.kr;
Further Information

Publication History

Received 6 March 2008
Publication Date:
11 June 2008 (online)

Abstract

This paper describes a new and efficient synthetic approach for biologically interesting natural (+)-machaeriol A and its unnatural enantiomer (-)-machaeriol A. The key strategies involve stilbene formation through a Horner-Wadsworth-Emmons reaction and trans-hexahydrodibenzopyran formation through a tandem aldol-hetero-Diels-Alder reaction.

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Spectral Data for Compound 1
1H NMR (300 MHz, CDCl3): δ = 7.48 (2 H, d, J = 7.3 Hz), 7.36 (2 H, dd, J = 7.7, 7.3 Hz), 7.27 (1 H, t, J = 7.7 Hz), 7.01 (1 H, d, J = 16.3 Hz), 6.93 (1 H, d, J = 16.3 Hz), 6.63 (1 H, d, J = 1.3 Hz), 6.44 (1 H, d, J = 1.3 Hz), 3.10 (1 H, br d, J = 12.6 Hz), 2.52 (1 H, ddd, J = 13.4, 11.1, 2.4 Hz), 1.90-1.87 (2 H, m), 1.68-1.64 (1 H, m), 1.52 (1 H, ddd, J = 11.4, 11.1, 2.1 Hz), 1.43 (3 H, s), 1.17-1.12 (2 H, m), 1.12 (3 H, s), 0.98 (3 H, d, J = 6.6 Hz), 0.81 (1 H, J = 13.4, 12.6 Hz). 13C NMR (75 MHz, CDCl3): δ = 155.8, 155.6, 137.7, 137.1, 129.0, 128.9, 128.5, 127.9, 126.9, 113.5, 108.8, 106.0, 77.8, 49.5, 39.3, 36.1, 35.9, 33.3, 28.5, 28.1, 23.0, 19.5. IR (neat): 3382, 3026, 2922, 2868, 1615, 1568, 1510, 1451, 1422, 1356, 1265, 1138, 1041, 961, 906, 878, 822, 737, 694 cm-1.