Methanol → (9H-fluoren-9-yl)methyl 4-(5-((2S,5R)-6-hydroxy-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-2-yl)-1,2,4-oxadiazol-3-yl)piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

BCl3 (8.5 ml, 8.5 mmol; 1 M in CH2Cl2) was added dropwise to a solution of (9H-fluoren-9-yl)methyl 4-(5-((2S,5R)-6-(benzyloxy)-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-2-yl)-1,2,4-oxadiazol-3-yl)piperidine-1-carboxylate (1.0 g, 1.7 mmol, 1.0 eq.) in dried CH2Cl2 (20 mL) at −78° C. The mixture was stiffed under N2 atmosphere at 0° C. for 6 hrs. Then, the reaction mixture was cooled to −78° C. and MeOH (2 mL) was added dropwise. The solvents were evaporated under vacuum at 0° C. to give ((9H-fluoren-9-yl)methyl 4-(5-((2S,5R)-6-hydroxy-7-oxo-1,6-diaza-bicyclo[3.2.1]octan-2-yl)-1,2,4-oxadiazol-3-yl)piperidine-1-carboxylate (970 mg) as a yellow solid, which was used directly in the next step. ESI-MS (EI−, m/z): 516.3 [M+H]−.

Provenance & Evidence