p-Toluenesulfonic acid → 5-Pentyl-2-(3',4'-difluorophenyl)-1,3-dioxane

Participants

Reaction Steps

Four solutions were prepared by dissolving 11.8 g (0.10 mol) of 2-pentylpropane-1,3-diol (prepared in Example 1 following the procedures of Steps 1-2), 14.2 g (0.10 mol) of 3,4-difluorobenzaldehyde, and 0.9 g (0.005 mol) of p-toluenesulfonic acid in methylene chloride (b.p. 40° C.), chloroform (b.p. 60° C.), benzene (b.p. 80° C.) and toluene (b.p. 111° C.), respectively. The solutions were treated following the procedures of Step 3 of Example 1 to yield mixtures of the cis and trans isomers of 5-pentyl-2-(3',4'-difluorophenyl)-1,3-dioxane. The yields of each mixture from its respective solvent and the ratio of the trans isomer to the cis isomer of each mixture are shown in Table 1.

Provenance & Evidence