Pyridine → 1,3-Dioxan-5-yl acetate

Participants

Reaction Steps

A mixture of 10.0 g (96 mmole) of glycerol formal, 8.35 g (105 mmole) of pyridine, and 20 ml of acetic anhydride was stirred at ambient temperature under protection from moisture. After a period ranging from a few hours to 5 days, the solution was fractionally distilled under vacuum. The early fractions consisted primarily of pyridine, acetic acid, and acetic anhydride. The bulk of the product distilled at 56°-57° (1.1 mm). The product fractions (10.8 g) were separated into the 5- and 6-membered ring isomers by preparative HPLC on silica gel in 3:1 hexane-ethyl acetate with recycling. Fractions were identified and checked for purity by analytical HPLC. In total 3.19 g (23%) of 1,3-dioxolane-4-methyl acetate (shorter retention time) and 5.23 g (37%) of 1,3-dioxan-5-yl acetate (longer retention time) were obtained. The structures were confirmed by NMR.

Provenance & Evidence