Isopropenyl-cyclohexane

SYNS FEMA No. 2962 ISOPULEGOL (FCC) 8(9)-p-MENTHEN-3-OL 1-METHYL-4-ISOPROPENYL-CYCLOHEXAN-3-OL... 

Die Xylol-sensibilisierte Bestrahlung von ( + )-l-Methyl-4-isopropcnyl-cyclohexen (Limonen) ftihrt in Methanol zu cis- und trans-4-Methoxy-4-methyl-l-isopropenyl-cyclohexan (28 bzw. 18% d.Th.)5. Das unumgesetzte Limonen wurde zu 84% racemisiert. 

HMD was originally produced by Du Pont as a coproduct in the manufacture of Qiana fiber. Du Pont subsequently sold the product to Bayer. In the 1990s MDA is hydrogenated by Air Products for Bayer (see Amines, aromatic-methylenedianiline). Commercial HMDI is a mixture of three stereoisomers. Semicommercial aUphatic diisocyanates include /n j -cyclohexane-l,4-diisocyanate (CHDI) and y -tetramethylxylylene diisocyanate (TMXDI). A coproduct in the production of TMXDI is y -isopropenyl-a,a-dimethylben2yl isocyanate (TMI), which can be copolymerized with other olefins to give aUphatic polyisocyanates. 

DIASTEREOSELECTIVE FORMATION OF TRANS-1,2-DISUBSTITUTED CYCLOHEXANES FROM ALKYLIDENEMALONATES BY AN INTRAMOLECULAR ENE REACTION DIMETHYL (1 R,2 R,5 R)-2-(2 -ISOPROPENYL-5 -METHYLCYCLOHEX-1 -YL)-PROPANE-1,3-DIOATE... 

Cyclohexan l-Brom-4-isopropenyl-l-methyl-2-nitroso- (dimer) X/l, 933, 936... 

In this context cis and trans refer to the alkyl substituents of the menthane skeleton thus the cw-epoxide has the oxirane ring on the side of the cyclohexane ring opposite to the isopropenyl group (120). 

The ipjo-attack on the activated isopropenyl group of the phenoxarsine (23) with TiCl4 in cyclohexane led to (24). The same compound was obtained when the arsinic acid (25), which was generated by formic acid-catalyzed ring expansion of (23) followed by oxidative workup, was reduced with PCI3 (Scheme 5) <90AG(E)689>. 

---