Acetone → Tert-butyl 6,6-dimethyl-4-oxo-4,6-dihydrofuro[3,4-d]thiazol-2-ylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of diisopropylamine (23.5 mL, 165 mmol) in tetrahydrofuran (200 mL) was added butyllithium (103 mL, 1.6 M in hexanes, 165 mmol) dropwise at −78° C. The solution was stirred at −78° C. for 30 minutes then transferred via cannula into a solution of methyl 2-(tert-butoxycarbonylamino)thiazole-4-carboxylate (Combi-Blocks, 14.2 g, 55 mmol) in tetrahydrofuran (300 mL) at −78° C. After stirring at −78° C. for 30 minutes, dry acetone (Acros, 16.2 mL, 220 mmol) was added dropwise and the reaction mixture was allowed to warm to room temperature and stirred overnight. The reaction mixture was quenched with saturated aqueous NH4Cl solution (200 mL) and the aqueous layer was extracted with ethyl acetate (4×200 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated. The residue was purified by column chromatography (SiO2, 0-100% ethyl acetate in hexanes) to afford the title compound MS (ESI+) m/z 285 (M+H)+.

Provenance & Evidence