Reaction #162136

Reaction equation

ethyl 1-methyl-2-oxo-cyclohexanecarboxylate

hydroxylamine hydrochloride

pyridine

→

37b

3a-methyl-4,5,6,7-tetrahydrobenzo[c]isoxazol-3(3aH)-one

Solvents

EtOH

Conditions

Workup

1. 1
   ConcentrationThe solution was concentrated in vacuo
2. 2
   Otherthe crude material was partitioned between water and EtOAc
3. 3
   ExtractionThe aqueous layer was extracted with EtOAc twice more
4. 4
   WashThe combined organic phases were washed with brine
5. 5
   Dryingdried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Concentrationconcentrated in vacuo
8. 8
   OtherThe resulting residue was purified via silica gel chromatography (0-35% EtOAc/hexanes)

Procedure

To a mixture of ethyl 1-methyl-2-oxo-cyclohexanecarboxylate, 37a, (2.05 g, 11.10 mmol) in EtOH (20 mL) was added hydroxylamine hydrochloride (0.97 g, 13.96 mmol) and pyridine (0.99 mL, 12.20 mmol). The mixture was heated to 65° C. overnight. The solution was concentrated in vacuo and the crude material was partitioned between water and EtOAc. The aqueous layer was extracted with EtOAc twice more. The combined organic phases were washed with brine, dried over MgSO4, filtered and concentrated in vacuo. The resulting residue was purified via silica gel chromatography (0-35% EtOAc/hexanes) to afford the desired product, 37b.

Source