CCN(C(C)C)C(C)C.[CH2:10]([Li])[CH2:11][CH2:12][CH3:13].[Si]([N:22]1[CH2:26][CH2:25][CH2:24][C:23]1=[O:27])(C(C)(C)C)(C)C.BrCCC=C>C1COCC1>[CH2:10]([CH:24]1[CH2:25][CH2:26][NH:22][C:23]1=[O:27])[CH2:11][CH:12]=[CH2:13]
DIPEA (0.393 mL, 2.76 mmol) was dissolved in THF (25 mL) and chilled to −78° C. n-Butyllithium (1.10 mL, 2.76 mmol) was then added, and the reaction was warmed to 0° C. and re-chilled to −78° C. 1-(tert-Butyldimethylsilyl)pyrrolidin-2-one (0.500 g, 2.51 mmol) was then added as a solution in THF (1 mL), and the reaction mixture was warmed to room temperature for 1 hour. The reaction was then re-cooled to −78° C., and 4-bromobut-1-ene (0.305 mL, 3.01 mmol) was added dropwise in THF (1 mL). The reaction mixture was slowly warmed to room temperature overnight. The reaction was concentrated to an oil and loaded onto CELITE®. Purification by flash column chromatography using 0-30% acetone/hexanes provided the title compound (0.218 g, 62%): 1H NMR (400 MHz, CDCl3) δ 6.15 (s, 1H), 5.82 (ddt, J=17.0, 10.2, 6.6 Hz, 1H), 5.09-4.87 (m, 2H), 3.42-3.24 (m, 2H), 2.44-2.25 (m, 2H), 2.24-2.05 (m, 2H), 1.99 (dddd, J=13.6, 9.4, 6.9, 4.1 Hz, 1H), 1.78 (dq, J=12.1, 8.4 Hz, 1H), 1.45 (dtd, J=13.7, 9.1, 5.5 Hz, 1H); 13C NMR (101 MHz, CDCl3) δ 180.44, 137.92, 115.13, 40.29, 40.16, 31.45, 30.05, 27.60; ESIMS m/z 138 ([M−H]−).
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