Boron trifluoride etherate → (2S)-3-chloro-1-(2,3-diphenylmethylenedioxyphenyl)-2-propanol

Temperature

-78 °C

n-Butyl lithium (2.3 mL of a 9.5M solution in hexane, 22 mmol) was added dropwise to a solution of 5.47 g of diphenylmethylenedioxybenzene (from step 1) in 75 mL of THF at 0° C. After 5 hr the solution was cooled to -78° C., and a solution of 1.85 g (20 mmol) of (S)-(+)-epichlorohydrin (Aldrich Chemical Co.) in 10 mL of THF was added. Boron trifluoride etherate (2.4 mL, 20 mmol) was then added dropwise, and the reaction was stirred for 1.5 hr. The reaction was quenched by addition of 50 mL of saturated NaHCO3, and the mixture was warmed to ambient temperature and partitioned between 100 mL of ether and 100 mL of water. The aqueous phase was extracted with ether (2×40 mL), and the ether extracts were combined and washed with brine, dried over MgSO4 and concentrated in vacuo to give a brown oil, which was purified by flash chromatography over silica gel, eluting with 15% ethyl acetate in hexane, to afford after removal of the solvent 4.23 g of the title compound as a light yellow oil (58% yield). MS (DCI/NH3) M/Z: 367 (M+H)+, 384 (M+NH4)+. 1H NMR (CDCl3, 300 MHz) δ: 2.3 (d, 1H), 2.9-3.0 (m, 2H), 3.5 (dd, 1H), 3.6 (dd, 1H), 4.1-4.23 (m, 1H), 6.65-6.85 (m, 3H), 7.37 (m, 6H), 7.55 (m, 4H).

1. customThe reaction was quenched by addition of 50 mL of saturated NaHCO3
2. temperaturethe mixture was warmed to ambient temperature
3. custompartitioned between 100 mL of ether and 100 mL of water
4. extractionThe aqueous phase was extracted with ether (2×40 mL)
5. washwashed with brine
6. dry with materialdried over MgSO4
7. concentrationconcentrated in vacuo
8. customto give a brown oil, which
9. customwas purified by flash chromatography over silica gel
10. washeluting with 15% ethyl acetate in hexane
11. customto afford

ORD record

ord-19bcef40dc914696af532edee57c8d0e

Source dataset

uspto-grants-1997_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05621133