反应详情

A cold solution of 1 part of 3-hydroxy-5-hydroxyimino-2-styrylcyclopent-1-eneheptanoic acid in 42.3 parts of dimethoxyethane is treated with a cold ethereal solution of diazomethane, prepared from 1.2 parts of N-nitrosomethylurea, 1.4 parts of potassium hydroxide and 2.5 parts of water. That mixture is allowed to react for 2 minutes, after which time, the cold excess diazomethane is decomposed by the careful addition of glacial acetic acid. The ethereal solution is washed with dilute aqueous sodium bicarbonate, then with water and dried over anhydrous sodium sulfate. The ether is removed and the crystalline residue is recrystallized from ethyl acetate-hexane to yield colorless crystals of methyl 3-hydroxy-5-hydroxyimino-2-styrylcyclopent-1-eneheptanoate. That compound melts at about 109°-110° and displays, in chloroform, absorption peaks in the infrared spectrum at about 3590 and 1735 reciprocal centimeters. It is further characterized by the following structural formula ##SPC19##

1. customto react for 2 minutes
2. washThe ethereal solution is washed with dilute aqueous sodium bicarbonate
3. dry with materialwith water and dried over anhydrous sodium sulfate
4. customThe ether is removed
5. customthe crystalline residue is recrystallized from ethyl acetate-hexane