| 摘要 |
PURPOSE:To obtain an unsaturated fatty acid useful as a material for blended spice for foods under relatively mild conditions by a short process economically, easily, in high yield, by heating an easily obtainable lactone as a raw material in the presence of an acid catalyst. CONSTITUTION:A lactone such as epsilon-decalactone, etc. shown by the formula I (n is 3 or 4; R is 1-10C alkyl or alkenyl) is heated in the presence of an acid catalyst at 100-300 deg.C, especially preferably 150-250 deg.C, and further distilled to give the desired compound such as 5- and 6-decenoic acid, etc. shown by the formula II (either of wavy lines is dobule bond). Activated clay, p-toluenesulfonic acid, benzenesulfonic acid, sulfuric acid, phosphoric acid, etc. may be cited as the acid catalyst, and an amount of it used is 0.1-10wt% based on the lactone shown by the formula I . |
