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

Temperature

-78 °C

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).

1. temperatureWith ice-cooling
2. stirringThe mixture is stirred at −78° C. for another 30 min
3. temperatureThe mixture is then slowly warmed to room temperature
4. stirringstirred for another 16 h
5. customThe solvent is removed
6. washwashed 2× with in each case 20 ml of 2 M HCl
7. dry with materialThe organic phase is dried over magnesium sulphate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue is purified by column chromatography (mobile phase: cyclohexane:ethyl acetate 10:1)

ORD record

ord-3f7c9987f948424b971dc65cff760d0d

Source dataset

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06376539B1