Carbon Dioxide → [4-(8-Ethyl-2,2,4,4-tetramethyl-chroman-6-yl-ethynyl) phenyl]acetic acid

Participants

Reaction Steps

Following general procedure R and using 6-bromo-8-cyclopropyl-3,4-dihydro-4,4-dimethylspiro[2H-1-benzopyran-2, 1′-cyclopropane] (Intermediate 42, 0.45 g, 1.48 mmol), anhydrous tetrahydrofuran (5 mL), 1.7M solution of tert-butyl lithium solution in pentane (1.74 mL, 2.96 mmol) and carbon dioxide generated from dry ice, followed by flash column chromatography over silica gel (230-400 mesh) using 50% ethyl acetate in hexane as the eluent, the title compound was obtained as a white solid (0.34 g, 85%).

Provenance & Evidence