C[C@@H](N(C)C)[C@@H](O)C1C=CC=CC=1.C(N(CC)CC)C.C[Si]([C:25]#[CH:26])(C)C.[Br:27][C:28]1[CH:33]=[CH:32][C:31]([C:34]2[O:38][N:37]=[C:36]([CH3:39])[C:35]=2[CH:40]=[O:41])=[CH:30][CH:29]=1>C1(C)C=CC=CC=1.[O-]S(C(F)(F)F)(=O)=O.[Zn+2].[O-]S(C(F)(F)F)(=O)=O>[Br:27][C:28]1[CH:29]=[CH:30][C:31]([C:34]2[O:38][N:37]=[C:36]([CH3:39])[C:35]=2[C@@H:40]([OH:41])[C:25]#[CH:26])=[CH:32][CH:33]=1Zinc triflate (0.75 g, 2.1 mmol), (1S,2R)-(+)-N-methylephedrine (0.41 g, 2.3 mmol) and triethylamine (0.23 g, 2.3 mmol) were stirred in toluene (10 mL) at room temperature for 2 hours. (Trimethylsilyl)acetylene (0.32 g, 2.3 mmol) was added and the reaction stirred for 15 minute then 5-(4-bromo-phenyl)-3-methyl-isoxazole-4-carbaldehyde (0.5 g, 1.9 mmol) was added and the reaction stirred at room temperature for 2 weeks. The reaction mixture was purified on by silica gel chromatography (0-20% EtOAc in hexanes) to afford the title product with 97.5% ee as measured by analytical chiral HPLC.
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