p-Toluenesulfonic acid → 4-(2,3-Dihydrothieno[3,4-b][1,4]dioxin-2-yl)-1-butanol
Reaction equation
[CH2:1]([O:4][C:5]1[C:9]([O:10][CH2:11][CH2:12][CH3:13])=[CH:8][S:7][CH:6]=1)CC.C(O)C(O)CC[CH2:18][CH2:19][OH:20].C1(C)C=CC(S(O)(=O)=O)=CC=1>>[O:10]1[CH:11]([CH2:12][CH2:13][CH2:18][CH2:19][OH:20])[CH2:1][O:4][C:5]2=[CH:6][S:7][CH:8]=[C:9]12Participants
4
Procedure
9.06 g (45.2 mmol) of 3,4-di-n-propoxythiophene, 30.3 g (226 mmol) of 1,2,6-hexanetriol and 0.09 g (0.5 mmol) of p-toluenesulphonic acid are heated to 150 to 165° C. (bath temperature) under N2 for 3 h. During this time, 5.8 g of distillate (substantially n-propanol) were collected. The cooled liquid was diluted with 50 ml of methylene chloride, washed to neutrality and to free it of hexanetriol with water and the organic phase was dried over Na2SO4. After filtering and evaporating the methylene chloride, the residue (6.73 g=74.8% of theory) was identified by 1H NMR spectroscopy (in CDCl3 against TMS) using δ=6.30 ppm (2H, thiophene H) and 2.85 ppm (1H, OH) as being substantially 4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)-1-butanol.