Tetrahydrothiophene → 2-Phenyl-1-oxaspiro[2.5]octane

Participants

Reaction Conditions

Reaction Steps

A mixture of 152 g (1.18 mol) of benzyl chloride, 108 g (1.18 mol) of tetrahydrothiophene and 0.225 L of water is stirred well at 85° C. until a homogeneous clear or slightly turbid single-phase solution of S-benzyltetrahydrothiophenium chloride has been obtained. The solution is cooled to 20° C. and is slowly added dropwise to a reaction mixture consisting of potassium hydroxide solution (prepared from 267 g (4.75 mol) of potassium hydroxide in 0.53 L of ice-water) and 467 g of cyclohexanone (4.75 mol) in 225 g of methanol. After the addition is complete, the reaction mixture is allowed to stand for 10 minutes until the phases have separated; the organic phase is separated off and subjected to fractional distillation. 181 g (80%) of 2-phenyl-1-oxa-spiro[2.5]octane are obtained in the form of a clear colourless oil.

Provenance & Evidence