反应详情

To a solution of ethyl 2-(4-bromophenyl)-3-[2-(chloromethyl)-1,3-dioxolan-2-yl]propanoate (1-3) (27 g, 71.5 mmol) cooled to −78° C. in DMF (200 mL) was added NaH (8.58 g, 214 mmol) and the reaction was allowed to slowly warm from −78° C. to rt. Once at rt, 1N NaOH (100 mL) was added and the reaction mixture was stirred over night. The crude reaction mixture was poured into saturated sodium bicarbonate and washed with chloroform. The aqueous layer was acidified with HCl, extracted with chloroform, dried over sodium sulfate filtered and concentrated. The crude residue was purified by column chromatography eluting with 1-50% EtOAc/Hexane. The appropriate fractions were concentrated and recrystallized from EtOAc/hexane to give 2-(4-bromophenyl)-5,8-dioxaspiro[3.4]octane-2-carboxylic acid (1-4) as a white solid. MS (M+H)+: 314.

1. temperatureto slowly warm from −78° C. to rt
2. customThe crude reaction mixture
3. washwashed with chloroform
4. extractionextracted with chloroform
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude residue was purified by column chromatography
9. washeluting with 1-50% EtOAc/Hexane
10. concentrationThe appropriate fractions were concentrated
11. customrecrystallized from EtOAc/hexane