Methyl iodide → (7aR)-Tetrahydro-3,3,6,6-tetramethyl-3H,5H-pyrrolo[1,2-c]oxazol-5-one

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Reaction Steps

To a solution of (R)-3,3-dimethyltetrahydropyrrolo[1,2-c]oxazol-5(3H)-one (D34) (1.3 g, 8.37 mmol) in dry THF (120 ml) cooled to −78° C., LDA 2M sol in THF/heptane (6.28 ml, 12.6 mmol) was added. The red solution was stirred at this temperature for 40 min before adding iodomethane (0.78 ml, 12.6 mmol). The reaction mixture was warmed to RT (40 min) then cooled to −78° C. prior addition of LDA 2M sol in THF/heptane (6.28 ml, 12.6 mmol). The mixture was stirred at −78° C. for 1 h before adding iodomethane (0.78 ml, 12.6 mmol) then the mixture was slowly warmed to RT and stirred overnight. The resulting solution was treated with NH4Cl sat sol (10 ml) and extracted with Et2O (3×10 ml). The organic phases were collected and washed with NaCl sat. sol, dried over Na2SO4 and evaporated in vacuo to afford the title compound (D35) (1.2 g).

Provenance & Evidence