Acetic Acid → 2-Phenylhexahydro-2,5-methanopentalene-3a-carboxylic acid

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Reaction Steps

To a stirred mixture of NaOH (2.4 g, 60.0 mmol), H2O (16 mL), and 1,4 dioxane (2 mL) at ice bath temperature was added Br2 (0.56 mL, 10.4 mmol) and stirred for 15 minutes. The resulting hypobromite solution was added dropwise to a stirred solution of 1-(1-phenyltricyclo[3.3.1.03,7]non-3-yl)ethanone obtained from preparation I (1.0 g, 4.0 mmol) in 1,4-dioxane (6 mL) at ice bath temperature. After stirring the reaction mixture at r.t. for 1 h, it was again cooled to ice bath temperature and quenched by adding AcOH (3.6 mL, 60 mmol). The reaction mixture was diluted with water and extracted with EtOAc. The combined organic layer was washed with brine, dried over Na2SO4, and the solvent was removed under reduced pressure to obtain 1-phenyltricyclo[3.3.1.03,7]nonane-3-carboxylic acid (0.62 g) in 64% yield. m/z (M+1) 243; 1H NMR (CDCl3) 300 MHz δ 7.40-7.25 (m, 4H), 7.25-7.18 (m, 1H), 2.90-2.86 (m, 1H), 2.54-2.48 (m, 1H), 2.38 (ddd, J=2.0, 2.0, 11.0 Hz, 1H), 2.20-2.05 (m, 4H), 1.98-1.78 (m, 5H), 1.70 (dd, J=2.8, 11.5 Hz, 1H).

Provenance & Evidence