Dichloromethane → Isohexane ethyl acetate

Participants

Reaction Conditions

Reaction Steps

9-BBN (4.63 ml of a 0.5 M solution in THF, 0.23 mmol) is added to a solution of [(S)-1-(1,3-Dioxo-1,3-dihydro-isoindol-2-ylmethyl)-3,3-dimethyl-pent-4-enyl]-carbamic acid tert-butyl ester (0.43 g, 0.116 mmol) in THF (15 ml) and the resulting colourless solution is stirred at room temperature overnight Anhydrous DMF (15 ml) is added to the solution, followed by 3 M aqueous K3PO4 solution (0.77 ml, 2.3 mmol), (R)-4-(4-Iodo-phenoxymethyl)-2,2-dimethyl-[1,3]dioxolane (267 mg, 0.28 mmol) and Pd(dppf)Cl2.DCM (47 mg, 0.058 mmol). The reaction is stirred at room temperature for 3 hours, 50° C. for 2 hours and then is allowed to cool to room temperature and filtered through a pad of Celite™ (filter material) which is washed with EtOAc (3×50 ml). The combined filtrates are washed with sat. aq. NaHCO3 solution (30 ml), dried (MgSO4) and the solvent removed in vacuo to afford a black oil. Multiple chromatography (SiO2, EtOAc/iso-hexane) yields [(S)-5-[4-((R)-2,2-Dimethyl-[1,3]dioxolan-4-ylmethoxy)-phenyl]-1-(1,3-dioxo-1,3-dihydro-isoindol-2-ylmethyl)-3,3-dimethyl-pentyl]-carbamic acid tert-butyl ester as a cream solid; [M+H—BOC]+ 481.

Provenance & Evidence