| 摘要 |
Derivatives of 3,3-pentamethylene-4-hydroxybutyric acid are prepared by converting cyclohexanediacetic acid to its anhydride, e.g. by refluxing with acetic anhydride or acetyl chloride, reacting the anhydride with an alkanol of at most 4 carbon atoms to form the corresponding monoalkyl ester of cyclohexanediacetic acid, reacting this with a suitable silver, potassium or mercury compound to give the silver, potassium or bivalent-mercury salt of the acid-ester, reacting this salt with bromine or iodine in a solvent under anhydrous conditions to form the corresponding lower alkyl 3,3-pentamethylene-4-halo-butyrate and reacting this with aqueous sodium or potassium hydroxide to form the sodium or potassium salt of 3,3-pentamethylene-4-hydroxy-butyric acid, which, if desired, may then be acidified and heated to form b ,b -pentamethylenebutyrolactone. Suitable metal compounds include silver nitrate, potassium hydroxide and mercuric oxide. Examples are given, and it is stated that the lactone may be converted to any desired salt of 3,3 - pentamethylene - 4 - hydroxy - butyric acid, such as the salts with alkaline earth metals, ammonia and amines. |
