O[C@@H:2]1[CH2:7][CH2:6][CH2:5][CH2:4][C@H:3]1[C:8]([O:10]CC)=[O:9].B(F)(F)F.[CH3:17][O:18][C:19]1[CH:20]=[C:21]([CH2:27][CH2:28][O:29]/[C:30](=N/[H])/[C:31](Cl)(Cl)Cl)[CH:22]=[CH:23][C:24]=1[O:25][CH3:26]>C1(C)C=CC=CC=1>[CH2:4]([C@@:3]1([C:8]([OH:10])=[O:9])[CH2:2][CH2:7][CH2:6][CH2:31][C@H:30]1[O:29][CH2:28][CH2:27][C:21]1[CH:22]=[CH:23][C:24]([O:25][CH3:26])=[C:19]([O:18][CH3:17])[CH:20]=1)[CH3:5]To ethyl (1R,2R)-2-hydroxycyclohexane-1-carboxylate (166) (1.7 g, 10 mmol) and BF3.EtO2 (280 mg, 250 μL, 2 mmol) in toluene (10 mL) was added dropwise a solution of 3,4-dimethoxyphenethoxy trichloroacetimidate (16) (3.26 g, 10 mmol) in toluene (15 mL). The resultant solution was stirred at ambient temperature for 2 hrs. The reaction mixture was then quenched with water (10 mL), the organic layer was collected, dried over anhydrous MgSO4 and concentrated in vacuo to give 3.71 g (quant. yield) of ethyl (1R,2R)-2-(3,4-dimethoxyphenethoxy)cyclohexane-1-carboxylic acid (167) which was used without further purification in the next step.
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