p-Toluenesulfonic acid → 1-Oxaspiro[5.5]undec-3-ene, 4-methyl-

Participants

Reaction Conditions

Reaction Steps

A mixture of p-TSA (20 g, 0.105 mol) and toluene (2 L) was heated to 115° C. To this mixture were added cyclohexanone (980 g, 10 mols) and isoprenol (946 g, 11 mols) and heated further for 3-6 h. Water was removed from the reaction azeotropically. The reaction mixture was then cooled to room temperature. The organic phase was washed with a 5% Na2CO3 solution, washed with water dried and concentrated and distilled further to provideto 4-methyl-1-oxaspiro [5.5] undec-3-ene (1.32 kg) having a purity of 98% (sum of the isomers) for a total yield of 80%.

Provenance & Evidence