(6bR*,9aR*)-6-(2-Benzyloxy-1-oxoethyl)-6b,9a-dihydro-5-hydroxy- 4-methoxyfuro[3,2-b]naphtho[2,1-d]furan-8(9H)-one
Margaret A. Brimble* and Josephine S. O. Park
School of Chemistry, University of Sydney, Eastern Ave, Camperdown, NSW 2006, Australia. Fax: (+61 3) 9351 3329; E-mail: [email protected]
Received: 20 January 2000 / Accepted: 2 February 2000 / Published: 23 February 2000
A solution of ceric ammonium nitrate (37 mg, 0.067 mmol) in water was added dropwise to a vigorously stirred solution of naphthol 1 (13 mg, 0.036 mmol) [1] in acetonitrile (2.2 ml) at room temperature and stirred for 15 min. Anhydrous magnesium sulfate was added and the resultant suspension immediately cooled to 0°C. After 1min., a solution of 2-trimethylsilyloxyfuran 2 (0.012 ml, 0.071 mmol) in acetonitrile (0.2 ml) was added dropwise and the resultant solution stirred at 0°C for 30 min. The reaction mixture was diluted with dichloromethane (5 ml), washed with water (2 x 3 ml) and dried over magnesium sulfate. The solvent was removed under reduced pressure to give an orange oil, which was then purified by flash chromatography using light petroleum-ethyl acetate (4:1) as eluent to afford the title compound 3 (9 mg, 60%) as a yellow oil.
IR (cm-1, neat): 3320w, 1785s, 1731, 1077.
1H NMR (200 MHz, CDCl3): 3.10-3.12 (2H, m, H9), 4.12 (3H, s, OMe), 4.67 (1H, d, Jgem 12.0 Hz, OCHAPh), 4.77 (1H, d, Jgem 18.1 Hz, COCHA), 4.88 (1H, d, Jgem 12.0 Hz, OCHBPh), 4.95 (1H, d, Jgem 18.1 Hz, COCHB), 5.43-5.49 (1H, m, H9a), 6.80 (1H, d, J6b,9a 6.1 Hz, H6b), 6.98 (1H, J3,2 7.0 and J3,1 2.0 Hz, H3), 7.28-7.60 (7H, m, H1, H2, Ph), 10.46 (1H, s, OH).
EI-MS: 420 (M+, 2%), 299 (M-CH2OBn, 25), 269 (M-C9H11O2, 13), 149 (COCH2OBn, 15), 91 (C7H7, 100), 57 (CH3CH2CO, 67), 43 (CH3CO, 54).
Anal. calc. for C24H20O7 MH+ (CI, NH3), 421.1286; found MH+, 421.1287.
Reference
| 1. | Brimble, M. A.; Oppen, E. Synth. Commun. 1997, 27, 989-1007. |
Sample availability: available from the authors.
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