Methyl formate → 5,5-(Ethylenedioxy)-3-Hydroxymethylene-4a-methyl-4,4a,5,6,7,8-hexahydro-3H-naphthalen-2-one

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Reaction Steps

A solution of 201 (20 g, 0.090 mmol) in THF (200 mL) was cooled to −5° C. in an ice/methanol bath. NaOMe (19.45 g, 0.360 mol) was added and the mixture stirred for 30 minutes. After slow addition of a cooled solution of methyl formate (55.5 mL, 0.900 mol) in 60 mL THF, the mixture was stirred at room temperature for 24 hours. The mixture was poured into ice-water-HCl (˜50 mL conc. HCl in 500 mL H2O), stirred for 5 minutes and then transferred to a separatory funnel. The aqueous layer was extracted with ether (3×100 mL) and the pooled organic extracts were washed with brine, dried (MgSO4), and concentrated. The yellow residue was flash chromatographed (0-50% EtOAc-hexanes) to yield 203 (5.88 g, 26%) as a yellow oil. 1H NMR (CDCl3) δ 1.22 (s, 3H), 1.6-1.9 (m, 4H), 2.02 (d, J=14 Hz, 1H), 2.2-2.5 (2H), 2.91 (d, J=14 Hz, 1H), 3.9-4.1 (m, 4H), 5.86 (d, J=2.0 Hz, 1H), 7.37 (s, 1H); 13C NMR (CDCl3) 188.72, 166.86, 165.35, 165.12, 124.59, 124.25, 111.92, 106.39, 65.33, 65.17, 65.04, 64.89, 46.00, 29.87, 21.33, 20.74, 20.59.

Provenance & Evidence