シトラール (cis-, trans-混合物)

化学的特性シトラールはリモネンとも呼ばれ特にレモンなどの柑橘類の果実に含まれる天然の化合物です化学的にはアルデヒドの一種でありその爽やかな柑橘系の香りは食品化粧品芳香剤さらには医薬品産業で広く利用されていますシトラールの化学式はC10H16Oで表され分子内には10個の炭素原子16個の水素原子そして1個の酸素原子が含まれています

化学的特性Citral occurs as (2Z)- and (2E)-isomers (citral a and b, respectively) analogous to the corresponding alcohols, geraniol and nerol: geranial (citral a), bp2.7 kPa 118–119 °C, d20 0.8888, n20 D 1.4898; neral (citral b), bp2.7 kPa 120 °C, d20 0.8869, n20 D 1.4869. Natural citral is nearly always a mixture of the two isomers. It occurs in lemongrass oil (up to 85%), in Litsea cubeba oil (up to 75%), and in small amounts inmany other essential oils. The citrals are colorless to slightly yellowish liquids, with an odor reminiscent of lemon. Since citral is an α,β-unsaturated aldehyde with an additional double bond, it is highly reactive and may undergo reactions such as cyclization and polymerization. Geraniol, citronellol, and 3,7-dimethyloctan-l-ol can be obtained from citral by stepwise hydrogenation. Citral can be converted into a number of addition compounds; the (Z)- and (E)-isomers can be separated via the hydrogen sulfite addition compounds.The condensation of citral with active methylene groups is used on an industrial scale in the synthesis of pseudoionones, which are starting materials for ionones and vitamins.

化学性质さわやかなレモン様