反应详情

To a solution of 4-tritylthio-2-azetidinone (3.5 g, 10.15 mmol) in tetrahydrofuran (8 ml) was added triethylamine (1.42 ml, 10.15 mmol) and glyoxylic acid hydrate (1.02 g, 10.15 mmol). The mixture was stirred at room temperature with 4 A mol. sieves* (volume of 8 ml) for 1 h and allowed to stand at room temperature overnight. The solidified mixture was diluted with methylene chloride and filtered; the filtrate was evaporated and the residue crystallized from pentane to give 5.18 g (98%) of title compound as a white solid mp 112°-5° C.; ir νmax : 3100-3600, and 1755 cm-1 ; 1Hmr (CDCl3) δ:7.3 (15H, m), 4.92 and 5.10 (1H, 2s), 4.50 (1H, dd, J=8 Hz, J=3 Hz), 3.0 (1H, dd, J=15 Hz, J=7 Hz), 3.1 (6H, q, J=7 Hz), 2.70 (1H, dd, J=15 Hz, J=3 Hz), 2.0-3.5 (2H, m) and 1.21 ppm (9H, t, J=7 Hz).

1. waitto stand at room temperature overnight
2. filtrationfiltered
3. customthe filtrate was evaporated
4. customthe residue crystallized from pentane