反应详情

温度

-30 °C

A solution of an (R)-binaphthol-dibromotitanium complex which had been prepared in the same manner as in Example 6 was cooled to -30° C. and added with 82 mg (1 mmole) of methylenecyclopentane (manufactured by Aldrich Corp.) and 88 mg (1 mmole) of methyl glyoxylate, followed by reaction for 3 hours. Then, 10 ml of an aqueous sodium hydrogen-carbonate solution was added to terminate the reaction. The reaction mixture was filtered through Celite and extracted with two 20 ml portions of diethyl ether and two 20 ml portions of ethyl acetate, and the extract was dried over anhydrous magnesium sulfate. Thereafter, the solvents were distilled off, and hexane was added to the residue to crystallize binaphthol. The remaining solution was purified by means of silica gel column chromatography to obtain 156 mg of methyl (R)-2-hydroxy-3-(l-cyclopentenyl)propionate. The yield was 92%.

1. customA solution of an (R)-binaphthol-dibromotitanium complex which had been prepared in the same manner as in Example 6
2. customfollowed by reaction for 3 hours
3. customto terminate
4. customthe reaction
5. filtrationThe reaction mixture was filtered through Celite
6. extractionextracted with two 20 ml portions of diethyl ether and two 20 ml portions of ethyl acetate
7. dry with materialthe extract was dried over anhydrous magnesium sulfate
8. distillationThereafter, the solvents were distilled off
9. additionhexane was added to the residue
10. customto crystallize binaphthol
11. customThe remaining solution was purified by means of silica gel column chromatography