| 摘要 |
1,125,699. Dehydration. CONTINENTAL OIL CO. 13 April, 1967 [30 June, 1966], No. 17008/67. Heading C2C. Catalytic partial dehydration of a linear C 4-30 polyol having two or three hydroxyl groups in the presence of an excess of a. monohydric alcohol to monohydric alcohol or carbonyl group containing hydrocarbon reducible to a monohydric alcohol, or mixtures thereof by contacting an oxide of a Group III(b) including the lanthanum and actinium series with the polyol in, the vapour phase at a temperature between 200‹ and 500‹ C. According to a preferred embodiment of the invention a straight chain C 6-30 primary alcohol containing a diol having a boiling point corresponding to that of the alcohol (e.g. the mixture of primary alcohols obtained by hydrolysis of an air oxidized reaction mixture prepared by growing aluminium trialkyls in the presence of ethylene) is treated as above to selectively dehydrate the diol to lower boiling derivatives which may optionally be hydrogenated prior to removal in conventional manner. The preferred catalysts are thoria, scandia, yttria or didymia optionally supported on a neutral base such as glass beads or an alumina, e.g. y-alumina, not active in the dehydration of alcohols. The purification of a mixture of 1-octanol containing 1,3-octanediol and the dehydration of 1,3 - octanediol in the presence of 1 - tetradecanol to give octadiene, 3-octanol, 1-octen-3-ol, 3-octanone, 1-hexanol, 2-heptanone together with unsaturated primary octenols is described.
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