1,3-Propanediol → 2-(4-(tert-Butyl)-2-(1,3-dioxan-2-yl)phenyl)-4,4-dimethyl-4,5-dihydrooxazole

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Reaction Steps

8.10 g (31.2 mmol) of 5-tert-butyl-2-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-benzaldehyde was weighed into a 500 mL round bottom flask fitted with a stir bar and Dean-Stark trap. Added 300 mL of benzene and stirred to obtain a clear yellow solution. Added 383 mg (1.52 mmol) of pyridinium p-toluenesulfonate. Added 11.3 mL (156 mmol) of 1,3-propanediol. Heated the solution to reflux for 17 h. Cooled to room temperature Washed the reaction mixture with 200 mL of 50% saturated aqueous NaHCO3, 200 mL of water, and 200 mL brine. Dried over MgSO4 and removed the solvent on rotavap. Purified by silica gel flash chromatography using isocratic elution with 10% EtOAc/CH2Cl2 to obtain 4.93 g of the title compound as a clear yellow resin. MS (ESI) 318 (M+H)+.

Provenance & Evidence