p-Toluenesulfonic acid → 1,1,3,3,5-Pentamethyl-1,3,3a,4,7,7a-hexahydro-isobenzofuran

Participants

Reaction Steps

2-[6-(1-Hydroxy-1-methyl-ethyl)-4-methyl-cyclohex-3-enyl]-propan-2-ol (720 g, 3.3 mol, obtained as detailed above) was loaded into a round bottom flask fitted with a Bidwell-Sterling trap and dissolved in toluene (1 L). An acid catalyst p-toluenesulfonic acid (pTSA, 40 g, 0.18 mol) was added and the mixture was heated to reflux. The reflux was maintained for 1.5 hours. Water was collected in the Bidwell-Sterling trap during this period. GC analysis indicated the completion of the reaction. The resulting mixture was reduced in volume and purified by fractional distillation to provide 1,1,3,3,5-pentamethyl-1,3,3a,4,7,7a-hexahydro-isobenzofuran (60 g, 9% yield).

Provenance & Evidence