Carbon Dioxide → 3-Methylbicyclo[1.1.1]pentane-1-carboxylic acid

To a solution of 1-iodo-3-methylbicyclo[1.1.1]pentane (1.62 g, 7.79 mmol; prepared according to Eur. J. Org. Chem. 1137-1155 (2000)) in diethyl ether (26 mL), a solution of tert-butyllithium (9.16 mL, 15.57 mmol, 1.7 M in pentane) was added over a period of 40 min at −78° C. After stirring the reaction mixture for 1 h at this temperature, carbon dioxide gas was bubbled through the reaction mixture for 5 min and then the mixture was allowed to warm to room temperature. The reaction mixture was extracted twice with a 5% aqueous sodium bicarbonate solution. The combined aqueous phases were acidified to pH 2-3 with concentrated hydrochloric acid at 0° C., saturated with sodium chloride, and extracted with diethyl ether. The combined organic phases were dried and, after evaporation of the solvent under reduced pressure, purified by column chromatography (0-20% ethyl acetate in hexanes) to afford 3-methylbicyclo[1.1.1]pentane-1-carboxylic acid (0.5 g, 3.96 mmol, 50.9% yield); 1H NMR (400 MHz, DMSO-d6) δ ppm 12.21 (s, 1H), 1.82 (s, 6H), 1.14 (s, 3H).

1. customwas bubbled through the reaction mixture for 5 min
2. extractionThe reaction mixture was extracted twice with a 5% aqueous sodium bicarbonate solution
3. customwere acidified to pH 2-3 with concentrated hydrochloric acid at 0° C., saturated with sodium chloride
4. extractionextracted with diethyl ether
5. customThe combined organic phases were dried
6. customafter evaporation of the solvent under reduced pressure
7. custompurified by column chromatography (0-20% ethyl acetate in hexanes)

ORDレコード

ord-23787b0dc2a646c8bd8187b2846c4347

出典データセット

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US09139534B2