p-Toluenesulfonic acid → 4,5-Dihydro-2-methoxy-5,5-dimethyl-1,3-benzodioxepin-7-yl methanesulphonate
Reaction equation
[CH3:1][S:2]([O:5][C:6]1[CH:11]=[CH:10][C:9]([OH:12])=[C:8]([C:13]([CH3:17])([CH3:16])[CH2:14][OH:15])[CH:7]=1)(=[O:4])=[O:3].[CH:18](OC)(OC)[O:19][CH3:20].C1(C)C=CC(S(O)(=O)=O)=CC=1>>[CH3:1][S:2]([O:5][C:6]1[CH:11]=[CH:10][C:9]2[O:12][CH:18]([O:19][CH3:20])[O:15][CH2:14][C:13]([CH3:17])([CH3:16])[C:8]=2[CH:7]=1)(=[O:4])=[O:3]Participants
4
Procedure
4-Hydroxy-3-(2-hydroxy-1,1-dimethylethyl)phenyl methanesulphonate (10.4 parts) (from Example 1) was reacted with trimethyl orthoformate (127 parts) in the presence of p-toluenesulphonic acid (0.05 parts) as in Example 20 to produce 4,5-dihydro-2-methoxy-5,5-dimethyl-1,3-benzodioxepin-7-yl methanesulphonate (9.5 parts, 79% yield) as a colourless oil.