Potassium Carbonate → HCID 89783639, compound

Participants

Reaction Steps

To a solution of (R)-6-(2-(benzyloxy)ethyl)-1-tosyl-5,6-dihydropyrrolo[3,4-b]pyrrol-4(1H)-one (724e, 3.51 g, 8.55 mmol) in MeOH (50 mL) in an ice bath was added K2CO3 (2.36 g, 17.10 mmol) in one portion. The resulting white suspension was stirred in an ice bath for 1 h and at RT for 1 h. The resulting suspension was filtered through a pad of Celite washing with MeOH. 10 g silica gel was added to the filtrate and concentrated in vacuo. The resulting solid was purified using an ISCO Combiflash RF (40 g Grace Reverlis column, using a gradient of 0-10% 2 M NH3/MeOH in DCM) affording (R)-6-(2-(benzyloxy)ethyl)-5,6-dihydropyrrolo[3,4-b]pyrrol-4(1H)-one (724f; 1.84 g, 7.17 mmol, 84% yield) as an orange-brown viscous oil. m/z (ESI, +ve) 257.1 (M+1)+. The material (724f) was further purified by chiral SFC (mobile phase CO2/30% MeOH (20 mM NH3), chiral column AS (250×30 mm), wave length 245 nm, flow rate 120 mL/min) The first eluting peak was collected and concentrated in vacuo to give (S)-6-(2-(benzyloxy)ethyl)-5,6-dihydropyrrolo[3,4-b]pyrrol-4(1H)-one (724g) (537 mg, 3.04 mmol, 24% yield, >99% ee) as an orange tar. The second eluting peak was collected and concentrated in vacuo to give (R)-6-(2-(benzyloxy)ethyl)-5,6-dihydropyrrolo[3,4-b]pyrrol-4(1H)-one (724) (780 mg, 3.04 mmol, 35% yield, >99% ee) as an orange tar. 1H NMR (400 MHz, CDCl3) δ ppm 8.46 (1H, br. s.), 7.33-7.44 (5H, m), 6.58 (1H, t, J=2.3 Hz), 6.32 (1H, dd, J=2.8, 1.9 Hz), 5.70 (1H, br. s.), 4.56 (2H, s), 4.52 (1H, dd, J=8.4, 4.7 Hz), 3.77 (2H, dd, J=6.7, 4.3 Hz), 1.90-2.07 (2H, m). m/z (ESI, +ve) 257.1 (M+1)+.

Provenance & Evidence