反应详情

温度

-5 °C

15.6 g of 1E was mixed with 150 ml of THF and 11.3 g of N,N-diisopropylethylamine. The mixture was cooled to -5° C. and 9.1 g of methyl chloroformate was added drop-by-drop to the stirred mixture, which then was stirred at 0° C. for two hours. The mixture then was poured over ice water and extracted with ether. The extract was dried (MgSO4), filtered and the solvent was evaporated. The residue was column chromatographed on silica gel, using a 1:4:20 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent, to give 1, as a tan solid, m.p.: 90°-92° C.

1. extractionextracted with ether
2. dry with materialThe extract was dried (MgSO4)
3. filtrationfiltered
4. customthe solvent was evaporated
5. customchromatographed on silica gel
6. additionv:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent
7. customto give 1