Lithium Hexamethyldisilazide → Methyl(1R,4S)-4-[(tert-Butoxycarbonyl)amino]-1-[(3R)-tetrahydrofuran-3-yl]cyclopent-2-ene-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a 1.00 M solution of lithium hexamethyldisilazide in tetrahydrofuran (34.8 mL, 34.8 mmol) under N2 at −78° C. was added a solution of methyl (1R,4S)-4-[(tert-butoxycarbonyl)amino]cyclopent-2-ene-1-carboxylate (4.0 g, 16 mmol) in tetrahydrofuran (20 mL). The resulting brown solution was stirred at −78° C. for 30 min before adding a solution of (3R)-3-iodotetrahydrofuran (3.75 g, 17.4 mmol) in THF (3 mL). The mixture was stirred for 10 min at −78° C. then kept in a freezer reading at −25° C. overnight. The reaction was quenched with saturated ammonium chloride, extracted with ether three times. The combined extracts were dried (MgSO4), filtered, concentrated and purified by flash column chromatography (EtOAc/Hexane) to provide the desired product (1.6 g, 31%). MS calculated for C16H25NO5: (M+H) 312.2; found 312.2.

Provenance & Evidence