A solution of N-(diphenylmethylene)aminoacetonitrile (5.14 g, 23.4 mmol) in DCM (12 ml) is treated with (R)-4-[4-(3-bromo-propyl)-phenoxymethyl]-2,2-dimethyl-[1,3]dioxolane (8.1 g, 24 mmol) in DCM (12 ml) and cooled to 0° C. 48% aqueous NaOH (20 ml) is added followed by benzyltriethylammonium chloride (530 mg, 2.4 mmol) and the resulting mixture is allowed to warm to room temperature. After stirring vigorously for 4 hours mixture is diluted with DCM (100 ml) and the aqueous portion is removed. The organic layer is washed with water (2×50 ml), brine, dried (MgSO4), filtered and concentrated in vacuo. The crude product is purified by chromatography on silica eluting with 15:1 iso-hexane/diethyl ether to 4:1 iso-hexane/diethyl ether to yield 2-(Benzhydrylidene-amino)-5-[4-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-phenyl]pentanenitrile as a yellow oil; 1H NMR (CDCl3): mix of diastereoisomers 1.39 (3H, s), 1.43 (3H,$), 1.71 (2H, m), 1.80-1.98 (2H, m), 2.52 (2H, tr, J=7.0 Hz) 3.90, (2H, m), 4.02 (1H, m), 4.10-4.22 (2H, m), 4.47 (1H, pent, J=6.9 Hz), 6.82 (2H, d, J=7.4 Hz), 7.05 (2H, d, J=7.4 Hz), 7.19 (2H, m), 7.35 (2H, tr, J=7.2 Hz), 7.40-7.50 (4H, m), 7.60 (2H, d, J=7.1 Hz).
