1,4-Dioxaspiro[4.5]decan-8-one → 8-Benzyl-1,4-dioxaspiro[4.5]decan-8-ol
Reaction equation
[CH2:1]([Mg]Cl)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:10]1[O:20][C:13]2([CH2:18][CH2:17][C:16](=[O:19])[CH2:15][CH2:14]2)[O:12][CH2:11]1>C1COCC1>[CH2:1]([C:16]1([OH:19])[CH2:17][CH2:18][C:13]2([O:20][CH2:10][CH2:11][O:12]2)[CH2:14][CH2:15]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A 0° C. solution of 2M benzylmagnesium chloride in THF (20 mL) was treated with a solution of 1,4-cyclohexanedione mono-ethylene ketal (6.24 g, 40 mmol) in THF (50 mL), warmed to room temperature, stirred overnight, quenched with saturated NH4Cl (100 mL), and extracted with ethyl acetate (3×100 mL). The combined extracts were washed with water and brine, dried (Na2SO4), filtered, and concentrated. The concentrate was purified by flash column chromatography on silica gel with 6:1 hexanes/ethyl acetate to provide the desired product (8.08 g, 81%). MS (CI) m/e 231(M−18)+, 249 (M+H) +, 266.2 (M+18)+.