It is easily oxidized to carvonol and carvone in humid air. When it reacts with sulfur, it loses water to form p-cymene, and also produces hydrogen sulfide and some sulfide.
When heated with inorganic acid, it is isomerized into α-terpinene with conjugated diene structure, which is easily oxidized to generate aromatic p-cymene. When limonene and maleic anhydride are heated, adducts generated by Diels-Alder reaction between maleic anhydride and α-terpinene can be obtained.
Limonene can usually react with olefins, in which both double bonds can react, or the conditions can be controlled so that only one double bond can react. When treated with anhydrous hydrogen chloride/hydrogen bromide, disubstituted olefins first add with hydrogen halide; However, when mCPBA is used for epoxidation, trisubstituted olefins are first epoxidized to produce limonene oxide. If mCPBA is excessive, both double bonds are epoxidized to obtain limonene dioxide.
The acyclic double bond of D- limonene can be added in toluene by trifluoroacetic acid according to the anti-Markov law. After the reaction, trifluoroacetate can be hydrolyzed with sodium hydroxide to obtain (S)- (? )-α-terpineol (terpineol).
Limonene can also be added with water in the presence of inorganic acid to produce α -terpineol and hydrated terpineol.
When limonene is treated with nitrosyl chloride, what is the intramolecular double bond between limonene and NO? Cl was added to generate 1- chloro -2- nitroso compound, α-chlorooxime was obtained through tautomerism, then unsaturated carvone oxime was obtained by removing hydrogen chloride with alkali, and finally the corresponding ketocarvone was obtained by hydrolyzing oxime with dilute sulfuric acid. This is the main method to prepare carvone in industry.