(R)-2-Methyl-CBS-oxazaborolidine → Trifluoromethanesulfonic acid 5-hydroxy-5,6,7,8-tetrahydronaphthalen-2-yl ester

Temperatur

0 °C

To a dry three-necked flask containing (R)-2-methyl-CBS-oxazaborolidine (Aldrich, 1.94 mL, 1.0 M in toluene, 1.93 mmol, 0.05 eq) under N2 was added a solution of borane-methylsulfide (BMS) (Aldrich, 3.30 mL, 34.80 mmol, 0.9 eq) in toluene (200 mL) through an additional funnel at RT. After the addition, the reaction was cooled to 0° C. A solution of trifluoro-methanesulfonic acid 5-oxo-5,6,7,8-tetrahydro-naphthalen-2-yl ester (11.37 g, 38.67 mmol, 1.0 eq) in THF (180 mL) was added drop-wise through an additional funnel. Following the addition, the reaction mixture was warmed to RT and stirred for additional 40 min, then quenched with MeOH. The solvent was removed in vacuo. The residue was treated with H2O (50 mL), and extracted with ether (3×150 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The title compound was obtained as an off-white solid after flash chromatography purification (16-22% EtOAc-hexane).

1. customTo a dry three-necked flask
2. additionAfter the addition
3. additionthe addition
4. temperaturethe reaction mixture was warmed to RT
5. customquenched with MeOH
6. customThe solvent was removed in vacuo
7. additionThe residue was treated with H2O (50 mL)
8. extractionextracted with ether (3×150 mL)
9. washThe combined organic layers were washed with brine
10. dry with materialdried over Na2SO4
11. filtrationfiltered
12. concentrationconcentrated in vacuo

ORD-Eintrag

ord-7abbfdf588b34683b1a34787007a1eec

Quelldatensatz

uspto-grants-2008_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07425631B2