Toluene → Non-2-yn-1-ol

Participants

Reaction Conditions

Reaction Steps

In a 250-mL flask equipped with a stir bar, I-Pr2NH (7.34 g, 72.5 mmol) and THF (20 mL) were stirred under argon and cooled to 0° C. A 2.5-M solution of n-BuLi in toluene (29.0 mL, 72.5 mmol) was added slowly to the stirring solution. The reaction was stirred for 30 min at 0° C. and then cooled to −78° C. in a dry ice/acetone bath. Then 1-octyne was added slowly via syringe to the reaction and a white precipitate formed. To dissolve the precipitate, HMPA (23.6 g, 132 mmol) was added in one portion. The cloudy solution was stirred under argon at −78° C. for 30 minutes before warming to 0° C. when the precipitate dissolved. A solution of paraformaldehyde (CH2O)n (5.94 g, 198 mmol) in THF (60 mL) was stirred under argon at −78° C. The alkynyllitheate was then added via cannula with positive argon pressure to the (CH2O)n solution. The reaction was then allowed to warm slowly to room temperature. The reaction was quenched with water and extracted with Et2O. The organic layers were combined, washed with water and brine, dried with MgSO4, and concentrated. This produced 24.4 g of orange oil. The product was purified with flash column chromatography on silica gel (10% Et2O in hexane) to give 5.07 g of amber oil (55%):

Provenance & Evidence