Citric Acid → (S)-5-Phenyl-1-(trimethylsilyl)pent-1-yn-3-ol

Participants

Reaction Conditions

Reaction Steps

Following a procedure of Trost (Trost, B. M. et al., J. Am. Chem. Soc. 128, 6745-6754 (2006)); n-butyllithium (2.5 M in hexanes, 474 μL, 1.18 mmol, 3 eq.) was added dropwise to a solution of (S)-5-phenylpent-1-yn-3-ol 86 (63.3 mg, 0.39 mmol, 1 eq.) in THF (1 ml) at −78° C. The mixture was allowed to warm to 0° C. and stirred 30 min before being cooled to −78° C. TMSCl (148.2 μL, 1.18 mmol, 3 eq.) was added dropwise and the mixture was allowed to warm to r.t. and stirred for 2 h. Citric acid (65 mg) in methanol (0.7 ml) was added and the mixture stirred for 1 h. The mixture was poured into a mixture of brine (3 ml) and Et2O (5 ml). The aqueous layer was extracted with Et2O (3×10 ml) and the combined organic phases were washed with brine (10 ml) before being dried (MgSO4), filtered and concentrated to give the crude product. This was purified by column chromatography on silica, eluting with petrol/Et2O (9:1), giving the title product 87 as a clear, colourless oil (18.5 mg, 15.5%). Analytical data consistent with the literature (Trost, B. M. et al., J. Am. Chem. Soc. 128, 6745-6754 (2006)).

Provenance & Evidence