Benzaldehyde → 1,3-Dioxan-5-ol, 2-phenyl-

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Reaction Steps

To a solution of benzaldehyde (150.0 g, 1.41 mol) in toluene, glycerol (160.0 g, 1.74 mol) was added followed by 4-methylbenzenesulfonic acid (1.0 g) and the mixture was vigorously stirred under reflux with a Dean-Stark water separator. The refluxing was continued until no more water separated in the condenser (6-8 h). The clear solution was treated with 4N NaOH until basic and the organic layer was washed with water (5×100 mL) followed by saturated sodium chloride solution and then dried over anhydrous sodium sulfate. Concentration of the organic layer resulted in an oil which was dissolved in hot isopropylether and then left in the freezer overnight. The colorless solid was filtered and washed with isopropylether to yield the title product as a colorless solid. Yield: 55.0 g (22%). m.p. 83°-84° C. [Lit. m.p. 83°-84° C.; J. S. Briamacombe, A. B. Foster and M. Stacey, Chem. & Ind., 1958, 122814 9]. 1H NMR (CDCl3) ε 3.1 (d, 1H, --OH), 3.7 (d, 1H Ar--CH), 4.3 (m, 4H, O--CH2), 5.6 (s, 1H, O--CH--O) and 7.4 (m, 5H, Ar--H). M/e: [M+H]+ =181.

Provenance & Evidence