In sharp contrast to the behavior of mono-and disubstituted 1, 3-dioxanes, acylation of 4, 4, 6- trimethyl-l, 3-dioxane (13) is a slow reaction that leads to a mixture of 14 and 15 in a ratio of 3: l. The reaction period for the room temperature cleavage of 13 had to be extended to 1 week (Table I, entries 7 and 8) in order to obtain even moderate (50%) conversion to product. However, even this rather sluggish reaction is a moderately regioselective ...
