| 摘要 |
<p>1,209,199. Olefinically unsaturated oxo compounds. BADISCHE ANILIN & SODA FABRIK A.G. 5 March, 1968 [6 March, 1967], No. 10554/68. Heading C2C. A process for the production of olefinically unsaturated oxo compounds which contain the carbon-carbon double bond in gamma-delta or delta-epsilon position to the oxo group comprises heating a 5,6-dihydro-4H-pyran in which at least one C atom linked to the C atom in the 6-position carries at least one hydrogen atom with 0À01 to 10% by wt. of water with reference to the dihydropyran, or with a corresponding amount of a substance which splits off water under the reaction conditions, e.g. a tertiary alcohol, at a pressure of 10 to 30 atmospheres at a temperature of 280‹ to 350‹ C. Examples prepare 6 - methylhept - 6 - en - 2 - one and 6 - methylhept - 5 - en - 2 - one, from 2,6,6 - trimethyl - 5,6 - dihydro - 4H - pyran, and 5,7,7 - trimethyl - oct - 4 - en - 1 - al and 5 - methylene- 7,7 - dimethyl - octan - 1 - al from 6 - methyl - 6 - neopentyl - 5,6 - dihydro - 4H - pyran.</p> |
