Sulfuric Acid → 5-(Carbomethoxy)-2,4,5,6-tetrahydro-cyclopenta[c]thiophene

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Reaction Steps

Dissolve 5-(carboxy)-2,4,5,6-tetrahydrocyclopenta[c]thiophene (3.95 g, 23.5mmol) in methanol (60 mL) and treat with dimethoxypropane (5.8 mL, 47 mmol)and sulfuric acid (0.8 mL). Stir at room temperature for 1 day. Evaporate the solvent in vacuo, dilute with methylene chloride (75 mL) and wash withsaturated sodium hydrogen carbonate (35 mL). Extract the aqueous phase withmethylene chloride (30 mL), wash combined organics with brine (30 mL) and dry (Na2SO4). Evaporate the solvent in vacuo and pass through aplug of silica gel to give 5-(carbomethoxy)-2,4,5,6-tetrahydro-cyclopenta[c]thiophene.

Provenance & Evidence