Acetone → (S)-4-((Benzyloxy)methyl)-2,2-dimethyl-1,3-dioxolane

Participants

Reaction Conditions

Reaction Steps

Benzyl alcohol (60.54 g, 0.56 mol) was dropped under ice cooling in a suspension of 60% sodium hydride (11.2 g, 0.28 mol) and DMF (300 ml). After emission of hydrogen gas, therein a DMF solution (25 ml) of (R)-3-chloro-1,2-propanediol (15.47 g, 0.14 mol, optical purity 98.7% e.e.) was dropped. The reaction temperature was raised to 60° C. and the mixture was stirred under heating for 2 hours. After completion of the reaction the mixture was cooled on ice bath and neutralized with 6% hydrochloric acid. After removal of water and DMF in vacuo, ethyl acetate was added to the residue, the insoluble materials were filtered off and the filtrate was condensed in vacuo. Thereto acetone (1500 ml) and p-toluenesulfonic acid (1.13 g) were added and the solution was stirred for 5 hours at 25° C. After the reaction was over, the reaction mixture was neutralized with triethylamine. After stirring for 5 minutes, acetone was removed in vacuo. The crude product was distilled to give 16.228 g of (S)-4-benzyloxymethyl-2,2-dimethyl-1,3-dioxolane (yield 52%, b.p. 110° C. at 0.3 mmHg).

Provenance & Evidence