Benzene → beta-DAMASCONE

Reaction equation

[CH3:1][C:2]1[CH2:7][CH2:6][CH2:5][C:4]([CH3:9])([CH3:8])[C:3]=1[C:10](=[O:14])/[CH:11]=[CH:12]\[CH3:13].C1C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>CCOCC>[CH3:1][C:2]1[CH2:7][CH2:6][CH2:5][C:4]([CH3:8])([CH3:9])[C:3]=1[C:10](=[O:14])/[CH:11]=[CH:12]/[CH3:13]

Participants

Procedure

Under an atmosphere of nitrogen, a solution containing 1.16 g. of cis-2,6,6-trimethyl-1-crotonyl-1-cyclohexene prepared according to Example 18, 12 ml. of dry benzene and 0.023 g. of p-toluensulfonic acid were stirred 48 hours at room temperature. The solution was diluted with ether, neutralised and washed as usual. The volatile components were removed in vacuo and distillation gave a 90% yield of trans-2,6,6-trimethyl-1-crotonoyl-1-cyclohexene, b.p. 78°-80°/0.001 Torr, the constants of which were found identical with those of the compound described in Example 12.