C([O:3][C:4](=O)[C:5]([C:8]1[CH2:9][CH2:10][O:11][CH2:12][CH:13]=1)([CH3:7])[CH3:6])C.[H-].[H-].[H-].[H-].[Li+].[Al+3].O.[OH-].[Na+]>O1CCCC1>[O:11]1[CH2:10][CH:9]=[C:8]([C:5]([CH3:7])([CH3:6])[CH2:4][OH:3])[CH2:13][CH2:12]1Step C To a solution of 2-(3,6-dihydro-2H-pyran-4-yl)-2-methyl-propionic acid ethyl ester (6 g, 30 mmol) in anhydrous tetrahydrofuran (75 mL) at 0° C. was added a tetrahydrofuran solution (1 M) of LiAlH4 (100 mL, 100 mmol) under nitrogen. The reaction mixture was heated at reflux for 3 h, then cooled to room temperature. Water and aqueous NaOH solution (2N) was added. The mixture was filtered to remove the precipitate, and the filtrate was concentrated. Water was added, and the mixture was extracted with ethyl acetate. The organic layer were separated, washed with water, aqueous HCl solution, brine, dried over MgSO4, and concentrated to give 2-(3,6-dihydro-2H-pyran-4-yl)-2-methyl-propan-1-ol as a brown oil (4.63 g, 98%).
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