Synlett 2007(6): 0992-0994  
DOI: 10.1055/s-2007-970767
LETTER
© Georg Thieme Verlag Stuttgart · New York

Formal Total Synthesis of Ovalcin by Carbohydrate Approach

Jhillu Singh Yadav*, Sreedhar Pamu, Dinesh Chandra Bhunia, Srihari Pabbaraja
Organic Division-I, Indian Institute of Chemical Technology, Hyderabad 500007, India
Fax: +91(40)27160387; e-Mail: yadavpub@iict.res.in;
Further Information

Publication History

Received 6 August 2006
Publication Date:
26 March 2007 (online)

Abstract

A formal total synthesis of ovalcin is described herein starting from readily available sugar ribose with selective zinc-mediated ring-opening reaction and Grubbs olefin metathesis as the key steps.

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Selected Spectroscopic Data
Compound 4: colorless oil; [α]D -57 (c 2.1 CHCl3), lit [7b] [α]D -60.0 (c 1.28, CHCl3). IR (CHCl3): 3458, 1452, 1380, 1247, 1114, 1014, 981 cm-1. 1H NMR (300 MHz, CDCl3): δ = 4.30 (s, 1 H), 4.02 (d, J = 9.0 Hz, 1 H), 3.44 (s, 3 H), 3.06 (d, J = 4.5 Hz, 1 H), 3.03 (d, J = 2.2 Hz, 1 H), 2.57 (d, J = 5.2 Hz, 1 H), 2.23 (td, J = 5.4 Hz, 1 H), 1.99 (br s, 1 H, OH), 1.73 (m, 2 H), 1.35 (m, 1 H), 0.97 (t, 9 H), 0.61 (q, 6 H). 13C NMR (75 MHz, CDCl3): δ = 85.23, 67.52, 66.76, 59.95, 57.71, 50.06, 28.90, 26.20, 6.74, 4.88. MS-FAB: m/z = 260 [M+].
Compound 11: colorless oil; [α]D -13.0 (c 2.5, CHCl3). IR (CHCl3): 3476, 2934, 1613, 1514, 1458, 1301, 1173, 931, 758 cm-1. 1H NMR (200 MHz, CDCI3): δ = 7.22 (d, J = 8.5 Hz, 2 H), 6.82 (d, J = 8.5 Hz, 2 H), 5.96 (m, 1 H), 5.24 (m, 2 H), 4.51 (m, 1 H), 4.43 (d, J = 1.5 Hz, 2 H), 4.17 (dd, J = 3.1, 7.0 Hz, 1 H), 3.77 (s, 1 H), 3.66 (m, 1 H), 3.40 (d, J = 5.4 Hz, 1 H), 2.17 (d, J = 5.4 Hz, 1 H), 1.48 (s, 3 H), 1.35 (s, 3 H). 13C NMR (75 MHz, CDCl3): δ = 159.30, 134.08, 130.00, 129.40, 119.45, 113.80, 108.67, 79.01, 68.76, 52.24, 27.18, 24.95. MS-FAB: m/z = 308 [M+].