ニトロアルカンとアクロレインのMichael反応による香料化合物 (4-オキソノナナール及びジャスモン酸メチル) の合成
1985 年 34 巻 2 号 p. 115-119
詳細
1985 年 34 巻 2 号 p. 115-119
4-Oxoaldehydes, which are important intermediates for the syntheses of terpenoids and jasmonoids, are prepared from the reaction of nitroalkane with acrolein catalyzed by tertiary-phosphine as tributylphosphine, tricyclohexylphosphine or triphenylphosphine, followed by Nef reaction of the resulting 4-nitro aldehyde ethylene acetals. The Michael reaction of nitroethane (1 a) with acrolein was carried out using a variety of tertiary-phosphines as catalysts in benzene at room temperature. Acetalization in situ gave 1, 1-ethylenedioxy-4-nitropentane (2a) in 68% yields. In the reaction of nitroalkane (1 b) (1g) with acrolein, 4-nitro ethylene acetals (2b) (2g) were obtained in 62-70% yields. 4-Nitroethylene acetals (2e), (2f) were subjected to an electrochemical oxidative Nef reaction to give 4-oxoaldehydes (4e), (4f). These compounds were converted respectively to 4-oxononanal and 2- hydroxy-5-pentyltetrahydrofuran, the latter being an essential oil found in watermelon. Dihydro- and cis-methyl jasmonate (7) were prepared from 4-oxoaldehydes (4).
