反应详情

1.63 g of the above (1S,4aS,7aR)-1-[1-(ethoxy)ethoxy]-7-[2-(hydroxy)ethyl]-1,4a,5,7a-tetrahydrocyclopenta[c]pyrane-4-carboxylic acid methylester were dissolved in dichloromethane followed by addition of 1.7 ml of pyridine and DMAP. Next, 1.0 ml of acetic anhydride were added followed by stirring for 3 hours at room temperature. The reaction mixture was then extracted with ether. After washing the organic phase with 2N aqueous hydrochloric acid, saturated aqueous sodium bicarbonate and brine, it was dried over anhydrous magnesium sulfate. After distilling off the solvent under reduced pressure, the residue was purified by silica gel chromatography to obtain a colorless oil from the hexane-ether eluate in the form of (1S,4aS,7aR)-7-[2-(acetoxy)ethyl]-1-[1-(ethoxy)ethoxy]-1,4a,5,7a-tetrahydrocyclopenta[c]pyrane-4-carboxylic acid methylester (1.65 g, yield: 89%). The physicochemical properties of this compound are described below.

1. extractionThe reaction mixture was then extracted with ether
2. washAfter washing the organic phase with 2N aqueous hydrochloric acid, saturated aqueous sodium bicarbonate and brine, it
3. dry with materialwas dried over anhydrous magnesium sulfate
4. distillationAfter distilling off the solvent under reduced pressure
5. customthe residue was purified by silica gel chromatography