Tetrahydrofuran → Ethyl 2-hydroxy-4-methyl-2-(trifluoromethyl)pent-4-enoate

Participants

Reaction Steps

A solution of ethyl trifluoropyruvate (125 g, 0.734 mol) in 2.0 L of THF was treated with methylallyl magnesium chloride (0.5 M in THF, 1.90 L, 0.954 mol) over 4 hours while the internal temperature was maintained below −60° C. The reaction mixture was allowed to reach room temperature overnight, concentrated in vacuo to remove THF, quenched with 1 L of saturated ammonium chloride solution, and extracted with three 1 L portions of diethyl ether. The combined organic phases were washed with 100 mL of brine, dried over magnesium sulfate, filtered, and concentrated in vacuo. Vacuum distillation at 60 mmHg afforded 100.1 g of 2-hydroxy-4-methyl-2-trifluoromethylpent-4-enoic acid ethyl ester as a clear oil (b.p. 97° C.-103° C., 60%).

Provenance & Evidence