To a solution of N-benzyl-2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)-N-[(1S)-1-phenylprop-2-en-1-yl]pent-4-enamide (5b) (230 mg) dissolved in Toluene (25 mL) at 80° C. under N2 was added Grubbs catalyst (2nd generation) (22 mg) and the reaction mixture was stirred at 80° C. for 2 h, then cooled to RT. DMSO (0.1 mL) was added to the reaction and the mixture stirred for 1 h, then concentrated. The crude product was directly purified via flash chromatography (gradient—5%, 10%, 15% EtOAc/hexanes) to give a diastereomeric mixture (1.5:1) of the title compound. (168 mg, 78%).
