Pyridine → p-Nitrobenzyl 2-(4-Acetylthio-2-oxo-1-azetidinyl)-2-chloroacetate

Participants

Reaction Steps

To a cooled (0°) and stirred solution of p-nitrobenzyl 2-(4-acetylthio-2-oxo-1-azetidinyl)-2-hydroxy-acetate (3.79 g., 10.7 mmole) in tetrahydrofuran (40 ml.) and dioxane (40 ml.) was added pyridine (0.97 ml., 12 mmole) followed by SOCl2 (1.43 g., 0.88 ml., 12 mmole). The mixture was stirred 30 minutes at 0°, the precipitate was removed and washed with toluene, and the combined filtrates were concentrated on a rotary evaporator to leave a yellow oil. Partial purification was achieved by filtering the residue over a silica gel pad and washing with chloroform. δ (ppm, CDCl3): 8.2 (2H, m, aromatic), 7.55 (2H, m, aromatic), 6.12 (1H, s, CHCl), 5.65 (1H, m, H-4), 5.35 (2H, two s, benzylic H), 3.62 (1H, dd, J3-3 =16, J3-4 cis =6, H-3), 3.08 (1H, m, H-3), 2.35 (3H, two s, CH3). The product was obtained as a mixture of two epimers.

Provenance & Evidence