Water → E-1-crotonoyl-2,2,6-trimethylcyclohexane
Reaction equation
[CH3:1][C:2]1([CH3:14])[CH2:7][CH2:6][CH2:5][C@H:4]([CH3:8])[C@@H:3]1[CH2:9][CH2:10][CH:11](O)[CH3:12].[OH2:15]>C1C=CC=CC=1>[C:9]([CH:3]1[CH:4]([CH3:8])[CH2:5][CH2:6][CH2:7][C:2]1([CH3:14])[CH3:1])(=[O:15])/[CH:10]=[CH:11]/[CH3:12]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 320 g (1.5 moles) of the ketol prepared in Example 2 in 1000 ml of benzene containing 2 g p-toluenesulphonic acid is heated in an apparatus for azeotropical water separation (Dean-Stark) till no more water separates. The reaction mixture is washed with a solution of sodium bicarbonate till neutral reaction and dried over anhydrous sodium sulfate. The solvent is removed by distillation at reduced pressure and the residue is distilled through a short Vigreux column. The product, cis, E-1-crotonoyl-2,2,6-trimethyl-cyclohexane (III, contains about 10% of the trans isomer) is collected at 76°C/1 mm; yield 273 g (94%). Recrystallization from pentane gives cis, E-1-crotonoyl-2,2,6-trimethylcyclohexane in high purity (m.p. 27°-28°C).
Workup
- washThe reaction mixture is washed with a solution of sodium bicarbonate till neutral reaction
- dry with materialdried over anhydrous sodium sulfate
- customThe solvent is removed by distillation at reduced pressure
- distillationthe residue is distilled through a short Vigreux column
- customis collected at 76°C/1 mm
- customRecrystallization from pentane
Sources & evidence
- ORD record
- ord-c82ba37fdbc9447a8d54c12d24d9acd0
- Source dataset
- uspto-grants-1976_05
- Patent number
- US03956392
Reaction notes
Loading…