Ethyl orthoformate → HCID 66870411, compound

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Reaction Steps

To a solution of (1R,3S,4S)-3-((S)-2-tert-Butoxycarbonyl-1-formyl-ethylcarbamoyl)-2-aza-bicyclo[2.2.1]heptane-2-carboxylic acid benzyl ester (698 mg) in dichloromethane (10 ml) was added triethyl orthoformate (720 mg) and p-toluenesulfonic acid monohydrate (6 mg). The resulting mixture was stirred at ambient temperature until no aldehyde remained by TLC. Saturated aqueous sodium bicarbonate solution was then added and the organic phase removed. This was washed with water and brine, dried (magnesium sulfate), filtered and concentrated under reduced pressure. This gave the sub-title compound as a pale yellow oil (635 mg, 78%); 1H NMR (400 MHz, d-6 DMSO) δ 0.96-1.15 (6H, m), 1.26-1.84 (16H, m), 2.20-2.50 (2H, m), 3.40-3.81 (5H, m), 4.10-4.28 (2H, m), 4.37 (1H, m), 4.88-5.14 (2H, m), 7.20-7.40 (5H, m), 7.65 (0.5H, d), 7.80 (0.5H, d).

Provenance & Evidence