反应详情

A solution containing 13.5 g of the product of Step B, 100 cm3 of toluene and 400 mg of hydrated p-toluene sulfonic acid was refluxed for 3 hours and then was evaporated to dryness under reduced pressure. The 11.2 g of residue were chromatographed over silica gel and was eluted with a 60-39-1 cyclohexane-ethyl acetate-acetic acid mixture. The eluate was evaporated to dryness under reduced pressure to obtain 9.6 g of (1R, cis) 2,2-dimethyl-3-[(Z)-2-(methoxy carbonyl)-ethenyl]-cyclopropane-carboxylic acid melting at 110° C. and having a specific rotation of [α]D20 =+75.4°±2° (c=1% in CHCl3).

1. temperaturewas refluxed for 3 hours
2. customwas evaporated to dryness under reduced pressure
3. customThe 11.2 g of residue were chromatographed over silica gel
4. washwas eluted with a 60-39-1 cyclohexane-ethyl acetate-acetic acid mixture
5. customThe eluate was evaporated to dryness under reduced pressure