(3aS)-1-methyl-3,3-diphenyl-hexahydropyrrolo(1,2-c)(1,3,2)oxazaborole → HCID 131726528, compound

Participants

Reaction Conditions

Reaction Steps

To a −30° C. cooled solution of 2-(tert-Butyl-dimethyl-silanyloxymethyl)-7-(2,2-dimethyl-propyl)-3,4-dihydro-2H-naphthalen-1-one (2.20 g, 6.09 mmol) in tetrahydrofuran (20 mL) was added (S)-2-methyl-Cbs-oxazaborolidine (1 M in toluene, 0.61 mL, 0.61 mmol) and a solution of borane-methyl sulfide complex (2 M in tetrahydrofuran, 2.15 mL, 4.3 mmol) in tetrahydrofuran (5 mL). The reaction mixture was heated at −20 to −5° C. for 5 h. The reaction mixture was quenched with methanol (8.3 mL) at −5° C. and then allowed to warm to room temperature and stirred overnight. The solvent was removed under reduced pressure. Flash column chromatography (silica gel, 0–5% ethyl acetate/hexanes) recovered 790 mg of ketone and provided chiral 2-(tert-Butyl-dimethyl-silanyloxymethyl)-7-(2,2-dimethyl-propyl)-1,2,3,4-tetrahydro-naphthalen-1-ol (980 mg, 70%): 1H NMR (300 MHz, CDCl3) δ 7.14 (s, 1H), 7.03–6.96 (m, 2H), 4.84 (d, J=2.5 Hz, 1H), 3.92–3.82 (m, 2H), 3.04 (d, J=3.7 Hz, 1H), 2.92–2.67 (m, 2H), 2.46 (s, 2H), 2.04–1.86 (m, 2H), 1.75–1.63 (m, 1H), 0.91 (s, 9H), 0.90 (s, 9H), 0.10 (s, 3H), 0.09 (s, 3H).

Provenance & Evidence