Triethylamine → t-Butyl 2-hydroxy-2-[(3R,4R)-3-phenylacetamido-4-[(RS)-tetrahydropyran-2-ylcarbonylmethylthio]azetidin-2-on-1-yl]acetate

Participants

Reaction Steps

(3R,4R)-3-Phenylacetamido-4-[(RS)-tetrahydropyran-2-yl-carbonylmethylthio]azetidin-2-one (1.7g) in 1,2-dichloroethane (20ml) was successively treated with 0.5M t-butyl glyoxylate in 1,2-dichlorethane (10ml) and triethylamine (50mg, 70μl) and monitored by t.l.c. (ethyl acetate) until no starting material remained. The reaction mixture was concentrated and flash chromatography (70% ethyl acetate in hexane, ethyl acetate) to afford the title compound as a yellow foam (1.9g, 82%); vmax (CH2Cl3) 3400 (w), 1780, 1736, 1687cm-1 ; δH (CDCl3) 1.49 (9H, s) overlapping 1.44-1.61 (4H, m), 1.8-2.0 (2H, m), 3.35-3.58 (3H, m), 3.65 (2H, s), 3.81-3.92 (1H, m), 4.01-4.06 (1H, m), 4.28-4.43 (1H, m), 4.99, 5.00, 5.07 (together 1H, 3d, J4.7Hz), 5.21, 5.32, 5.33 (together 1H, 3d, J6.8, 7.7, 7.6Hz), 5.42, 5.50 (together 1H, 2dd, J4.8, 8.7Hz, 6.35, 6.36, 6.61 (together 1H, 3d, J8.7Hz) and 7.27-7.38 (5H, m).

Provenance & Evidence