[Br:1][C:2]1[CH:3]=[CH:4][C:5]([OH:11])=[C:6]([C:8](=[O:10])[CH3:9])[CH:7]=1.[C:12]([CH:16]1[CH2:20][CH2:19][C:18](=O)[CH2:17]1)([CH3:15])([CH3:14])[CH3:13].N1CCCC1>CO>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:11][C:18]1([CH2:19][CH2:20][CH:16]([C:12]([CH3:15])([CH3:14])[CH3:13])[CH2:17]1)[CH2:9][C:8]2=[O:10]A mixture of 1-(5-bromo-2-hydroxy-phenyl)-ethanone (573 mg, 2.68 mmol), 3-tert-butylcyclopentanone (750 g, 5.36 mol) and pyrrolidine (362 mg, 5.092 mol) in methanol was refluxed overnight. The reaction mixture was removed in vacuo. The residue was diluted with an equal volume of H2O and then added HCl until pH=1. The mixture was extracted with EtOAc. The organic layer was dried over anhydrous Na2SO4, filtered, and evaporated to give 6-bromo-3′-tert-butylspiro[chroman-2,1′-cyclopentan]-4-one (0.8 g, 89%). 1H NMR (CDCl3): 0.77 (s, 9H), 1.34 (m, 1H), 1.48 (m, 2H), 1.63 (m, 2H), 1.81 (m, 2H), 2.09 (m, 2H), 2.72 (m, 2H), 6.73 (t, 1H), 7.47 (d, 1H), 7.89 (s, 1H).
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