Ethyl 3-[2,4-bis(benzyloxy)-6-(4-nitrophenoxy)phenyl]-5-hydroxy-4,5-dihydroisoxazole-5-carboxylate → Ethyl 3-[2,4-bis(benzyloxy)-6-(4-nitrophenoxy)phenyl]isoxazole-5-carboxylate

Participants

Reaction Steps

A stirred solution of ethyl 3-[2,4-bis(benzyloxy)-6-(4-nitrophenoxy)phenyl]-5-hydroxy-4,5-dihydroisoxazole-5-carboxylate (8.5 g, 14 mmol) and tosic acid hydrate (5.5 g, 29.5 mmol, 2.1 eq.) in toluene (150 mL) was refluxed for 6 hours. After cooling, the solution was washed with 1 M Na2CO3 solution then with brine. The solvent was removed and the residue was columned over a small pad of silica gel eluting with hexane/ethyl acetate 5/1 to provide the title compound (6.3 g, 79% yield).

Provenance & Evidence