Synlett 2005(14): 2260-2262  
DOI: 10.1055/s-2005-871965
LETTER
© Georg Thieme Verlag Stuttgart · New York

An Expeditious Enantiospecific Total Synthesis of (+)-7-epi-Goniofufurone

Kavirayani R. Prasad*, Shivajirao L. Gholap
Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India
Fax: +91(80)23600529; e-Mail: prasad@orgchem.iisc.ernet.in;
Further Information

Publication History

Received 27 April 2005
Publication Date:
13 July 2005 (online)

Abstract

Stereoselective synthesis of styryl lactone, (+)-7-epi-goniofufurone was achieved in high yield via simple transformations from tartaric acid. The key step involves the successive stereoselective reduction of ketones with borohydride and selectride.

12

The minor isomer was removed by simple crystallization from hexane-EtOAc.

13

We anticipated that the addition of vinyl magnesiumbromide to 9 followed by a stereoselective reduction of the ketone and RCM would yield the intermediate 14. However, addition of vinyl magnesium bromide to 9 proceeded with low yield. Full details of this strategy will be discussed in a future article.

14

All new compounds exhibited satisfactory spectral data. 8: [α]D +23 (c 1, CHCl3). 1H NMR (300 MHz, CDCl3): δ = 1.41 (s, 3 H), 1.50 (s, 3 H), 3.00 (s, 3 H), 3.17 (s, 3 H), 5.16 (d, J = 5.7 Hz, 1 H), 5.934 (d, J = 5.4 Hz, 1 H), 7.40-7.65 (m, 3 H), 8.05-8.15 (m, 2 H). 13C NMR (75 MHz): δ = 26.40, 35.97, 37.13, 75.04, 76.59, 77.43, 79.45, 112.56, 128.55, 129.41, 133.69, 134.94, 168.25, 196.38. Anal. calcd for C21H34NO4Si: C, 64.97; H, 6.91. Found: C, 65.28; H, 7.02. 9: [α]D +67.5 (c 1, CHCl3). 1H NMR (300 MHz, CDCl3): δ = -0.14 (s, 3 H), -0.04 (s, 3 H), 0.84 (s, 9 H), 1.26 (s, 3 H), 1.34 (s, 3 H), 2.84 (s, 3 H), 2.99 (s, 3 H), 4.44 (d, J = 6.6 Hz, 1 H), 4.72-4.88 (m, 2 H), 7.15-7.40 (m, 5 H). 13C NMR (75 MHz): δ = -5.15, -4.85, 18.21, 25.71, 26.43, 26.71, 35.78, 36.96, 73.23, 74.14, 82.03, 110.97, 127.29, 127.52, 127.71, 140.59, 169.04. Anal. calcd for C21H35NO4Si: C, 64.08; H, 8.96. Found: C, 64.10; H, 9.21. 11: [α]D +38.9 (c 1.5, CHCl3). 1H NMR (300 MHz, CDCl3): δ = -0.12 (s, 3 H), 0.00 (s, 3 H), 0.82 (s, 9 H), 1.10 (s, 3 H), 1.32 (s, 3 H), 1.33-1.50 (m, 1 H), 1.85-2.15 (m, 3 H), 3.09 (br s, 1 H), 3.64 (dd, J = 8.1 Hz, 2.4 Hz 1 H), 4.10 (dd, J = 8.1 Hz, 5.4 Hz 1 H), 4.76 (d, J = 5.1 Hz, 1H), 4.80-5.00 (m, 2 H), 5.67 (ddt, J = 16.8 Hz, 10.2 Hz, 6.9 Hz, 1 H), 7.15-7.30 (m, 5 H). 13C NMR (75 MHz): δ = -4.99, -4.85, 18.26, 25.79, 27.04, 27.39, 29.87, 33.87, 69.33, 75.54, 79.25, 80.57, 109.13, 114.79, 127.40, 127.78, 127.88, 138.14, 139.97. 13: [α]D +11.7 (c 0.6, CHCl3). 1H NMR (300 MHz, CDCl3): δ = 0.00 (s, 3 H), 0.11 (s, 3 H), 0.90 (s, 9 H), 1.17 (s, 3 H), 1.34 (s, 3 H), 3.87 (dd, J = 8.1, 2.4 Hz, 1 H), 4.46 (dd, J = 8.1, 5.7 Hz, 1 H), 4.52 (q, J = 2.0 Hz, 1 H), 4.94 (d, J = 5.7 Hz, 1 H), 6.07 (dd, J = 5.7 Hz, 1.8 Hz, 1 H), 7.26 (dd, J = 5.7, 1.8 Hz, 1 H), 7.25-7.45 (m, 5 H). 13C NMR (75 MHz): δ = -4.97, -4.94, 18.27, 25.79, 26.27, 26.99, 75.08, 75.11, 80.03, 81.47, 110.23, 122.14, 127.27, 128.03, 139.38, 153.10, 172.82. Anal. calcd for C22H33O5Si: C, 65.31; H, 7.97. Found: C, 65.26; H, 7.80.