| 摘要 |
1,136,345.α-Methylene aldehydes and alcohol derivatives. INTERNATIONAL FLAVORS & FRAGRANCES Inc. 18 Jan., 1967 [25 Jan., 1966], No. 2753/67. Heading C2C. Preparation of compounds of the formula wherein R is alkyl, alkenyl, hydroxyalkyl or alkoxyalkyl each having 5 to 10 carbon atoms, by reacting an aldehyde of the formula R.CH 2 .CHO with formaldehyde or a source of formaldehyde in the presence of ammonia or a primary or secondary amine of or salts of these. Typical of the catalysts used are the hydroxide, chloride or acetate of ammonia, methylamine hydrochloride, dimethylamine or its hydrochloride and diethylamine. The formaldehyde is used as an aqueous solution or may be derived in situ from paraformaldehyde. The methylene double bond may be selectively hydrogenated, e.g. with hydrogen in the presence of nickel or palladium, or the aldehydic carbonyl group selectively reduced to an alcohol group, e.g. with metal hydrides such as lithium aluminium hydride, singly or simultaneously. Examples describe the preparation of 2-methyene decanal; 2-methylene heptanal; 3,7-dimethyl- 2-methylene-6-octenal followed by hydrogenation to 2,3,7-trimethyl -6- octenal and reduction to 3,7 - dimethyl - 2 - methylene - 6 - octanol and 2,3,7-trimethyl-6-octenol; 2-methylene dodecanal; 2-methylene undecanal; 3,7-dimethyl-2- methylene octanal; 3,7-dimethyl-2-methylene-7- hydroxy - octanal; 2,3,7-trimethyl-7-hydroxyoctanol; 3,5,5-trimethyl-2-methylene hexanal andα-octyl acrolein. |
