Water → Tert-butyl 1-oxa-6-azaspiro[2.6]nonane-6-carboxylate

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Reaction Steps

to a stirred solution of trimethylsulfoxonium iodide (56.1 g, 255 mmol) in anhydrous DMSO (150 ml) was added a mixture of NaH (18.5 gram 1.5 equiv., 60% in mineral oil) under a nitrogen atmosphere. The mixture was stirred at 65° C. for 1 hour, whereafter compound 2 (32 g, 150 mmol) was added as a solution in DMSO (10 ml). The mixture was refluxed overnight under a nitrogen atmosphere. The solution was allowed to reach room temperature, water was added and the mixture was extracted with diethyl ether (3×200 ml). The combined organic layer was washed with H2O, with brine and dried over Na2SO4. The Et2O was evaporated to yield 82.1 gram (32 g, 95%) compound 3. 1H-NMR (300 MHz, CDCl3): δ (ppm)=1.45 (s, 9H, BOC); 1.50-2.10 (m, 6H), 2.60-2.70 (m, 2H), 3.5-3.60 (m, 2H).

Provenance & Evidence