| 摘要 |
<p>1,273,952. Preparation of omni-trans-canthaxanthine. RHONE-POULENC S.A. 19 April, 1971 [2 March, 1970], No. 22732/71. Heading C2C. Omni-trans-canthaxanthine is prepared by treating a mixture of isomeric canthaxanthines with an organic liquid which is solvent or isomers of canthaxanthines other than the omni-trans-isomer, e.g. a hydrocarbon, ketone, an ester or an ether, separating off any undissolved omni-trans-isomer, heating the resultant solution of the canthaxanthine isomers and thereafter isolating the omni-trans-isomer which is formed during heating. A mixture of isomeric canthaxanthines may be prepared by refluxing beta-carotene and chloroform containing iodine under nitrogen followed by addition of sodium periodate.</p> |
