O[C:2]1([CH3:13])[CH2:7][CH2:6][CH:5]([C:8](OCC)=[O:9])[CH2:4][CH2:3]1.C(N(S(F)(F)[F:20])CC)C.CO.[BH4-].[Li+]>ClCCl.C(OCC)(=O)C.O1CCCC1>[F:20][C:2]1([CH3:13])[CH2:7][CH2:6][CH:5]([CH2:8][OH:9])[CH2:4][CH2:3]1
A solution of ethyl 4-hydroxy-4-methylcyclohexanecarboxylate (2.50 g, 13.42 mmol) in dichloromethane (35 mL) at 0° C. was added with diethylaminosulfur trifluoride (14.2 mL, 107.40 mmol) slowly under nitrogen. The resulting mixture was stirred for 24 hours. The reaction mixture was diluted with ethyl acetate (100 mL) and poured into ice (200 g). The organic layer was washed with saturated sodium bicarbonate (3×100 mL) and brine (100 mL); dried with anhydrous sodium sulfate; filtered and concentrated in vacuo to provide the crude product as an oil; which was dissolved in anhydrous tetrahydrofuran (60 mL) and anhydrous methanol (1.10 mL, 26.8 mmol). To the mixture was added lithium borohydride (4 M solution in tetrahydrofuran, 6.70 mL, 26.8 mmol) dropwise and the resulting mixture was refluxed under nitrogen for 4 hours. The reaction mixture was cooled to ambient temperature and quenched with water and then 3 M aqueous hydrochloric acid solution. The mixture was diluted with ethyl acetate (150 mL) and the organic layer was washed with saturated sodium bicarbonate (2×100 mL) and brine (100 mL); dried with anhydrous sodium sulfate; filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography (2:1 hexanes:ethyl acetate) to provide the title compound as a colorless oil (0.66 g, 34%): 1H NMR (300 MHz, CDCl3) δ 3.50-3.43 (m, 2H), 1.97-1.86 (m, 1H), 1.85-1.71 (m, 2H), 1.69-1.52 (m, 4H), 1.49-1.24 (m, 5H), 1.20-1.03 (m, 1H).
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