Benzyl Bromide → cis-1-Benzyl-8-oxabicyclo[4.3.0]nonan-9-one

Participants

Reaction Conditions

Reaction Steps

Under argon, a solution of diisopropylamine (3.85 ml, 27.5 mmol) in 20 ml of dry THF is cooled to 0° C. and slowly admixed with butyllithium (11 ml, 27.5 mmol, 2.5M in hexane). With ice-cooling. This solution is stirred for 15 min and then cooled to −78° C. and a solution of cis-8-oxabicyclo[4.3.0]nonan-9-one (3.5 g, 25 mmol) in 10 ml of THF is added dropwise. The mixture is stirred at −78° C. for another 30 min and then mixed with benzyl bromide (3.27 ml, 27 mmol). The mixture is then slowly warmed to room temperature and stirred for another 16 h. The solvent is removed and the residue is taken up in 20 ml of dichloromethane and washed 2× with in each case 20 ml of 2 M HCl. The organic phase is dried over magnesium sulphate, filtered and concentrated. The residue is purified by column chromatography (mobile phase: cyclohexane:ethyl acetate 10:1).

Provenance & Evidence