(3aS)-1-methyl-3,3-diphenyl-hexahydropyrrolo(1,2-c)(1,3,2)oxazaborole → HCID 10261627, compound

Borane dimethylsulfide complex (2.75 mL, 28.6 mmol) was added at room temperature to a stirred solution of (S)-2-methyl-CBS-oxazaborolidine (2.87 mL, 1M) in dry THF (50 mL). The resulting solution was stirred at room temperature to 10 mins before a solution of 3-chloro-1-(2-thienyl)-1-propanone (2.5 g, 14.3 mmol) in dry THF (100 mL) was added dropwise over 1 hr. After complete addition the resulting solution was stirred at room temperature for a further 1 hr before the solvent was removed in vacuo. The residue was taken up in ether (200 mL) and washed with NH4Cl (sat, 100 mL). The organic phase was dried (MgSO4) and concentrated in vacuo. The residue was purified by flash chromatography eluting silica gel with hexane:ether [7:3] to yield a colourless oil (2.1 g, 84%); Optical purity determined by capillary electrophoresis to be 83% ee; δH (300 MHz, CDCl3) 7.25 (1H, d, Ar), 7.08–6.9 (2H, m, Ar), 5.28–5.20 (1H, m, CHO), 3.80–3.52 (2H, m, CH2), 2.35–2.12 (2H, m, CH2).

1. additionwas added dropwise over 1 hr
2. additionAfter complete addition the resulting solution
3. customwas removed in vacuo
4. washwashed with NH4Cl (sat, 100 mL)
5. dry with materialThe organic phase was dried (MgSO4)
6. concentrationconcentrated in vacuo
7. customThe residue was purified by flash chromatography
8. washeluting silica gel with hexane

ORD record

ord-5bab886afd064899be3d7a8c0052c7be

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07037932B2