Tetrabutylammonium Fluoride → tert-butyl N-tert-butoxycarbonyl-N-[(3S,7S,8R,9S)-8-hydroxy-9-methyl-7-(1-naphthylmethyl)-2-oxo-1,5-dioxonan-3-yl]carbamate

HRID 58957Notes

Reaction equation

HRID 58957 reaction equation
[C:1]([O:5][C:6]([N:8]([C@H:16]1[CH2:24][O:23][CH2:22][C@H:21]([CH2:25][C:26]2[C:35]3[C:30](=[CH:31][CH:32]=[CH:33][CH:34]=3)[CH:29]=[CH:28][CH:27]=2)[C@@H:20]([O:36][Si](C(C)C)(C(C)C)C(C)C)[C@H:19]([CH3:47])[O:18][C:17]1=[O:48])[C:9](=[O:15])[O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:7])([CH3:4])([CH3:3])[CH3:2].CCCC[N+](CCCC)(CCCC)CCCC.[F-]>C1COCC1.[Na+].[Cl-]>[C:11]([O:10][C:9]([N:8]([C@H:16]1[CH2:24][O:23][CH2:22][C@H:21]([CH2:25][C:26]2[C:35]3[C:30](=[CH:31][CH:32]=[CH:33][CH:34]=3)[CH:29]=[CH:28][CH:27]=2)[C@@H:20]([OH:36])[C@H:19]([CH3:47])[O:18][C:17]1=[O:48])[C:6](=[O:7])[O:5][C:1]([CH3:3])([CH3:4])[CH3:2])=[O:15])([CH3:12])([CH3:13])[CH3:14]

Participants

5

Procedure

To a solution of tert-butyl N-tert-butoxycarbonyl-N-[(3S,7S,8R,9S)-9-methyl-7-(1-naphthylmethyl)-2-oxo-8-triisopropylsilyloxy-1,5-dioxonan-3-yl]carbamate (2.54 g, 3.70 mmol) in THF (18.5 ml) was added TBAF (1.94 g, 7.41 mmol, 1M in THF) at room temperature. The reaction was stirred for 3.5 h, diluted with a ½ sat. aqueous NaCl solution (10 mL), and extracted with EtOAc (3×10 mL). The combined extracts were dried over Na2SO4, filtered, and concentrated to dryness under reduced pressure. The resulting clear oil was purified by flash chromatography (SiO2, 0→50% acetone/hexanes) to afford tert-butyl N-tert-butoxycarbonyl-N-[(3S,7S,8R,9S)-8-hydroxy-9-methyl-7-(1-naphthylmethyl)-2-oxo-1,5-dioxonan-3-yl]carbamate (1.41 g, 72%) as a white solid: 1H NMR (400 MHz, CDCl3) δ 8.11 (dd, J=8.5, 1.4 Hz, 1H), 7.87-7.79 (m, 1H), 7.72 (d, J=8.1 Hz, 1H), 7.54-7.41 (m, 2H), 7.42-7.27 (m, 2H), 5.19 (dd, J=8.8, 5.7 Hz, 1H), 5.00-4.88 (m, 1H), 4.10 (dd, J=11.9, 5.8 Hz, 1H), 3.89 (dd, J=12.0, 8.7 Hz, 1H), 3.68-3.51 (m, 4H), 2.79 (t, J=12.2 Hz, 1H), 2.58-2.51 (m, 1H), 2.15 (q, J=8.7, 7.4 Hz, 1H), 1.51 (d, J=6.4 Hz, 3H), 1.46 (s, 18H); 13C NMR (101 MHz, CDCl3) δ 169.95, 152.69, 135.84, 134.02, 132.04, 128.77, 127.46, 127.16, 126.03, 125.56, 125.25, 124.04, 83.17, 77.69, 76.26, 73.23, 70.87, 57.38, 46.90, 33.38, 27.92, 18.67; ESIMS m/z 553 ([M+Na]+).

Workup

  1. extractionextracted with EtOAc (3×10 mL)
  2. dry with materialThe combined extracts were dried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated to dryness under reduced pressure
  5. customThe resulting clear oil was purified by flash chromatography (SiO2, 0→50% acetone/hexanes)

Sources & evidence

ORD record
ord-1a0bd112c5904656af22358033a8d61c
Source dataset
uspto-grants-2016_09
Patent number
US09439422B2

Reaction notes

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