Preparation of polyunsaturated ketones
    4.
    发明授权
    Preparation of polyunsaturated ketones 失效
    多不饱和酮的制备

    公开(公告)号:US4431844A

    公开(公告)日:1984-02-14

    申请号:US361249

    申请日:1982-03-24

    CPC分类号: C07C49/203 C07C45/74

    摘要: An improved process for the preparation of unsaturated ketones of the general formula I ##STR1## where R.sup.1 is --CH.sub.3, ##STR2## and R.sup.2 and R.sup.3 are different and each is H or --CH.sub.3, by reacting an aldehyde of the general formula II ##STR3## with a molar excess of acetone or methyl ethyl ketone at an elevated temperature in the presence of an aqueous alkali metal hydroxide solution, wherein (a) all the reactants are mixed thoroughly, (b) the temperature is kept at from 10 to 120.degree. C. above the boiling point of the lowest-boiling component and (c) the pressure is kept at from p to 100 bar, where p is the vapor pressure of the mixture at the reaction temperature.The products methylpseudoionone, dimethylpseudoionone, pseudoirone, methylpseudoirone and dimethylpseudoirone are useful scents and scent intermediates. In addition, pseudoionone is an important intermediate for the industrial preparation of vitamin A, and 6-methyl-hepta-3,5-dien-2-one is a sought-after aromatic.

    摘要翻译: 制备通式I(I)的不饱和酮的改进方法,其中R 1为-CH 3,R 2和R 3不同,各自为H或-CH 3,通式 在碱金属氢氧化物水溶液的存在下,在升高的温度下用摩尔过量的丙酮或甲基乙基酮制备式II(II)化合物,其中(a)所有反应物充分混合,(b)温度为 保持在最低沸点组分的沸点以上10至120℃,和(c)压力保持在p至100巴,其中p是反应温度下混合物的蒸气压。 产物甲基假ion酮,二甲基假ion酮,假呋酮,甲基假酮和二甲基假酮是有用的香味和香味中间体。 此外,假雄酮是维生素A工业制备的重要中间体,6-甲基 - 庚-3,5-二烯-2-酮是一种追求的芳香族。