Hexamethylphosphoramide → HCID 131729992, compound

Participants

Reaction Steps

A solution of triethylsilyl acetylene (6.25 g, 8 mL, 44.7 mmol) in anhydrous tetrahydrofuran (150 mL) was mixed with a 2.5 M solution of n-butyl lithium (19.6 mL, 49.2 mmol) in hexane at −70° C. in argon. After stirring for 15 min at this temperature hexamethyl phosphoric triamide (19.4 g, 18.8 mL, 108 mmol) was added and the mixture stirred a further 15 min. A solution of 2-((S)-3-bromo-2-methylpropoxy)tetrahydropyrane (10.6 g, 44.7 mmol) in anhydrous tetrahydrofuran (40 mL) was added in drops to this solution and this was the slowly heated to room temperature. After adding saturated ammonium chloride solution (40 mL), the mixture was concentrated to low volume in a vacuum, the residue taken up in water (150 mL) and extracted with cyclohexane/diethyl ether (1:1.3×100 mL). The combined organic phases were dried with sodium sulphate and concentrated to low volume in a vacuum. The raw product (11 g) was purified by flash chromatography (400 g, 20×7.5 cm) with ethyl acetate/cyclohexane (1:30).

Provenance & Evidence