Hydrochloric Acid → HCID 86739990, compound

Participants

Reaction Steps

A solution of 200 mg of 3-(p-nitrophenylsulfonyl)-7,7-dimethoxybicyclo[3.2.0]hept-2-en-2-carboxylic acid, diphenylmethyl ester, in 5 mL of methylene chloride was diluted with 20 mL of acetic acid. Aqueous hydrochloric acid (4N, 3 mL) was added, the mixture was stirred for 1 hr at room temperature, and then evaporated to dryness at 25°. The residue was partitioned between methylene chloride and water and the organic layer was washed with brine, dried (Na2SO4), and evaporated. The residue was dissolved in a small amount of 5% methanol in methylene chloride and treated with an excess of diphenyldiazomethane to esterify any free acid present. After nitrogen evolution ceased, the reaction mixture was evaporated to dryness and the residue was dissolved in methylene chloride-ether to give a solution from which precipitated 127 mg (69.3%) of 3-(p-nitrophenylsulfonyl)-7-oxobicyclo[3.2.0]hept-2-en-2-carboxylic acid, diphenyl methyl ester, as colorless crystals. IR (Nujol mull): 1730, 1780 cm-1 ; NMR (80 MHz; CDCl3): δ 2.5-3.6 (5H, m), 4.7 (1H, m), 7.0 (1H, s), 7.2-7.5 (10H, m), 8.0 (2H, d, J=9), and 8.23 (2H, d, J=9). ##STR26##

Provenance & Evidence