(3aR,5R,7aS)-5-[(Benzyloxy)methyl]-7a-(2,4-difluorophenyl)hexahydro-1H-pyrano[3,4-c][1,2]oxazole → [(2R,4R,5S)-5-amino-2-[(benzyloxy)methyl]-5-(2,4-difluorophenyl)tetrahydro-2H-pyran-4-yl]methanol

HRID 538020Notes

Reaction equation

[CH2:1]([O:8][CH2:9][C@@H:10]1[O:18][CH2:17][C@:13]2([C:19]3[CH:24]=[CH:23][C:22]([F:25])=[CH:21][C:20]=3[F:26])[NH:14][O:15][CH2:16][C@@H:12]2[CH2:11]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1>C(O)(=O)C.[Zn]>[NH2:14][C@@:13]1([C:19]2[CH:24]=[CH:23][C:22]([F:25])=[CH:21][C:20]=2[F:26])[CH2:17][O:18][C@@H:10]([CH2:9][O:8][CH2:1][C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=2)[CH2:11][C@H:12]1[CH2:16][OH:15]

Participants

Conditions

Temperature: 40 °C

Procedure

Compound C5 (48.1 g, 133 mmol) was dissolved in acetic acid (444 mL) and treated with zinc powder (113 g, 1.73 mol). The reaction mixture, which had warmed to 40° C., was allowed to cool to room temperature and stir for 16 hours. Insoluble material was removed via filtration through a pad of diatomaceous earth, and the pad was washed with ethyl acetate (3×500 mL). The combined filtrates were neutralized with saturated aqueous sodium bicarbonate solution (2.5 L), and the aqueous layer was extracted with ethyl acetate (3×500 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (1 L), dried over sodium sulfate, filtered, and concentrated in vacuo to provide the product as a thick yellow oil, which was used in the following reaction without additional purification. Yield: 48.7 g, assumed quantitative. 1H NMR (400 MHz, CDCl3), characteristic peaks: δ 7.62-7.80 (br m, 1H), 7.28-7.39 (m, 5H), 6.94-7.06 (m, 1H), 6.83 (ddd, J=12.7, 8.5, 2.6 Hz, 1H), 4.61 (AB quartet, upfield doublet is broadened, JAB=12.2 Hz, ΔνAB=30.5 Hz, 2H), 4.22 (dd, J=11.6, 2.2 Hz, 1H), 3.83-3.92 (br m, 1H), 3.62-3.73 (br m, 1H), 3.56 (dd, J=10.2, 3.5 Hz, 1H), 3.34-3.41 (m, 1H), 2.26-2.43 (br m, 1H), 2.00-2.17 (br m, 1H), 1.65 (ddd, J=14.1, 4.5, 2.5 Hz, 1H).

Workup

temperatureto cool to room temperature
customInsoluble material was removed via filtration through a pad of diatomaceous earth
washthe pad was washed with ethyl acetate (3×500 mL)
extractionthe aqueous layer was extracted with ethyl acetate (3×500 mL)
washThe combined organic layers were washed with saturated aqueous sodium chloride solution (1 L)
dry with materialdried over sodium sulfate
filtrationfiltered
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-86a7e2cf582643318fa645082ee8ad4f
Source dataset: uspto-grants-2014_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08865706B2

Reaction notes

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