O[C:2](C)(C#C)[CH2:3][C:4]1[CH:5]=[C:6]([CH:10]2[CH2:14][CH2:13][CH2:12][N:11]2[C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH:7]=[N:8][CH:9]=1.[H-].[Na+].C1(C)C=CC=CC=1.CC(C)=O>C1(C)C=CC=CC=1>[C:3]([C:4]1[CH:5]=[C:6]([CH:10]2[CH2:14][CH2:13][CH2:12][N:11]2[C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH:7]=[N:8][CH:9]=1)#[CH:2]5-(2-Hydroxy-2-methyl-3-butynyl)-3-(1-tert-butyloxycarbonyl-2-pyrrolidinyl)pyridine (495 mg, 1.5 mmol) was dissolved in toluene (30 mL) and catalytic sodium hydride (10 mg) was added. The solution was heated until several milliliters of toluene-acetone mixture was removed by distillation. The mixture was cooled to 25° C. and water (20 mL) and ethyl acetate (40 mL) were added. The organic phase was separated and the aqueous layer extracted with ethyl acetate (2×40 mL) and the combined organic extracts were washed with brine (20 mL), dried (MgSO4) and concentrated in vacuo. The crude product was purified by silica gel column chromatography with ethyl acetate:hexane (1:3) as eluant to afford 5-ethynyl-3-(1-tert-butyloxycarbonyl-2-pyrrolidinyl)pyridine as an oil (250 mg, 61%). LRMS (EI) m/e 217 (M+ +H --isobutylene), 216 (M+ --isobutylene); 1H NMR (CDCl3, 300 MHz): δ 8.59 (b-s, 1H), 8.42 (d, J=1.5 Hz, 1H), 7.59 (b-s, 1H), 4.94 (b-m, 0.5H), 4.77 (b-m, 0.5H), 3.64 (b-m, 2H), 3.21 (s, 1H), 2.39 (m, 1H), 1.75-2.0 (b-m, 3H), 1.46 (s, 3H), 1.21 (s, 6H).
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