Mechanism of cyclic acetal formation.

The importance of the cyclic acetals in relation to the chemistry of the carbohydrates is well recognized and their synthesis has been the subject of much experiment and study.In earlier work dealing with the formation of cyclic acetals by the action of acetylene on polyhydroxy compounds in the presence of a catalyst, an interesting speculation as to the mechanism of this reaction was brought forward. With acetylene and ethylene glycol, for example, it was assumed that the first change involves the addition of one hydroxyl to the unsaturated acetylene linkage with formation of the intermediate hydroxy-ethyl Tinyl ether. [...