p-Toluenesulfonic acid → 2-[(4S)-2,2-diethyl-1,3-dioxolan-4-yl]ethanol

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-1,2,4-butanetriol intermediate 67a (6.76 g, 63.68 mmol) in freshly distilled pentan-3-one (320 mL) was added p-toluenesulfonic acid (p-TSA) (6.06 g, 31.84 mmol). The reaction mixture was stirred at 53° C. for 16 hours, then Et3N (10 mL) was added and the reaction mixture stirred at ambient temperature for 10 minutes. The reaction mixture was concentrated under reduced pressure. Gradient flash chromatography (CH2Cl2/MeOH, 100:0 to 97:3 to 95:5) afforded the protected alcohol intermediate 67b (9.84 g, 89%) as a colorless oil.

Provenance & Evidence