Br[C:2]([F:9])([F:8])[C:3]([O:5][CH2:6][CH3:7])=[O:4].BrC(Br)C.[CH:14]12[CH2:23][CH:18]3[CH2:19][CH:20]([CH2:22][CH:16]([CH2:17]3)[CH:15]1C=O)[CH2:21]2.B(OC)(OC)[O:27][CH3:28].Cl>[Zn].C(OCC)(=O)C.O1CCCC1>[C:14]12([CH:28]([OH:27])[C:2]([F:9])([F:8])[C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH2:15][CH:16]3[CH2:17][CH:18]([CH2:19][CH:20]([CH2:22]3)[CH2:21]1)[CH2:23]2A mixture of 40 g of ethyl bromodifluoroacetate, 3.7 g of dibromoethane and 50 g of tetrahydrofuran was added dropwise to a mixture of 13 g of zinc, 29 g of 2-adamantanecarbaldehyde, 60 mL of trimethyl borate, and 50 g of tetrahydrofuran at a temperature of 50° C., followed by stirring for 10 hours at 60° C. Thereafter, 100 g of 5 wt % hydrochloric acid was added to quench the reaction. Ethyl acetate, 200 g, was added to the reaction solution, from which the organic layer was extracted. The organic layer was washed with saturated sodium chloride water and then with water. The reaction solution after washing was concentrated under reduced pressure, obtaining 23 g of the target compound, ethyl 3-(1-adamantyl)-2,2-difluoro-3-hydroxypropionate as oily matter (yield 54%).
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