Methyl morpholine oxide → Tert-butyl 4-oxo-6-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)spiro[chroman-2,4'-piperidine]-1'-carboxylate

Participants

Reaction Steps

To a solution of 1.0 g of tert-butyl 4-hydroxy-6-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)-spiro[chroman-2,4′-piperidine]-1′-carboxylate in 40 ml of THF-CH3CN (1:1) ar rt were added 2.0 g of MS 4A, 435 mg of NMO, and 88 mg of TPAP, and the reaction mixture was stirred at rt overnight. The mixture was filtered through a Celite pad, washed with CHCl3 and CHCl3-MeOH (9:1), and the filtrate was concentrated in reduced pressure. The residue was purified by column chromatography on silica gel using a mixture of hexane-AcOEt (100/0-0/100) as eluent to give the intended compound as a colorless solid.

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