4-Bromo-1-chloro-2-(4-ethoxy-benzyl)-benzene → HCID 66884302, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-bromo-1-chloro-2-(4-ethoxy-benzyl)-benzene from step C (3.6 g, 11.1 mmol) in THF (60 ml) under N2 at −78° C. was added dropwise BuLi (2.5 M in hexanes, 4.4 ml, 11.1 mmol). After 30 minutes, aldehyde from step B (2.4 g, 64% clean, 5.1 mmol) in THF (20 ml) was added dropwise, and the reaction was stirred for 30 min at −78° C., allowed to warm to room temperature and stirred for 60 minutes, quenched with sat. aq. NH4Cl, diluted with Et2O, and washed with H2O and brine. The combined aqueous washes were back extracted with Et2O, which was washed by the same sequence. The combined organic extracts were dried over MgSO4, filtered, and concentrated under vacuum. The residue was purified by flash chromatography (120 g SiO2, 0-20% EtOAc:Hexanes, 75 minutes, 85 ml/min) to give clean (S)-[(3aS,5S,6R,6aS)-6-(tert-butyl-dimethyl-silanyloxy)-2,2-dimethyl-tetrahydro-furo[2,3-d][1,3]dioxol-5-yl]-[4-chloro-3-(4-ethoxy-benzyl)-phenyl]-methanol (0.84 g, 1.5 mmol, 30%) plus the C5 epimer (0.83 g) and some mixed fractions (0.51 g).

Provenance & Evidence