N-Fluorobenzenesulfonimide → Tert-butyl((3aR,4R,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)diphenylsilane

HRID 470180Notes

Reaction equation

HRID 470180 reaction equation
[C:1]([Si:5]([O:18][C@@H:19]1[C@H:26]2[C@H:22]([O:23][C:24]([CH3:28])([CH3:27])[O:25]2)[CH:21]=[C:20]1I)([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)([CH3:4])([CH3:3])[CH3:2].C1C=CC(S(N(S(C2C=CC=CC=2)(=O)=O)[F:40])(=O)=O)=CC=1.[Li]CCCC>C1COCC1>[C:1]([Si:5]([O:18][C@@H:19]1[C@H:26]2[C@H:22]([O:23][C:24]([CH3:28])([CH3:27])[O:25]2)[CH:21]=[C:20]1[F:40])([C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 588007N-FluorobenzenesulfonimideHCID 67251766Tert-butyl((3aR,4R,6aR)-5-iodo-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)diphenylsilaneHCID 178418339Butyllithium

Product 1

HCID 58329285Tert-butyl((3aR,4R,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)diphenylsilane

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

Tert-butyl((3aR,4R,6aR)-5-iodo-2,2-dimethyl-4,6a-dihydro-3H-cyclopenta[d][1,3]dioxol-4-yloxy)diphenylsilane (5-4) (1.4 g, 2.7 mmol, 1 equiv) was dissolved in dry THF (18 mL) and N-fluorobenzenesulfonimide (1.0 g, 3.2 mmol, 1.2 equiv) was added. The resulting mixture was cooled to −78° C. and BuLi (3.2 mL, 8.0 mmol, 3 equiv, 2.5 M in hexanes) was added dropwise over 10 minutes. The mixture was stirred at the same temperature for 1 hour. Upon disappearance of the starting material, the reaction was quenched with the addition of 20 mL NH4Cl, extracted with EtOAc (3×20 mL), dried over MgSO4, filtered and concentrated. The crude residue was purified by flash chromatography (80 g SiO2, 0-50% EtOAc in hexanes) to yield tert-butyl((3aR,4R,6aR)-5-fluoro-2,2-dimethyl-4,6a-dihydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)diphenylsilane (5-5) as a colorless oil. 1H NMR (500 MHz, CDCl3): δ 7.82 (d, J=5 Hz, 2H); 7.75 (d, J=6.5 Hz, 2H); 7.35-7.44 (m, 6H); 5.27 (s, 1H); 4.77 (dd, J=6.0, 2.0 Hz, 1H); 4.39 (t, J=6.0 Hz, 1H); 4.46 (td, J=6.0, 2.0 Hz, 1H); 1.52 (s, 3H); 1.35 (s, 3H); 1.10 (s, 9H).

Workup

  1. customUpon disappearance of the starting material, the reaction was quenched with the addition of 20 mL NH4Cl
  2. extractionextracted with EtOAc (3×20 mL)
  3. dry with materialdried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated
  6. customThe crude residue was purified by flash chromatography (80 g SiO2, 0-50% EtOAc in hexanes)

Sources & evidence

ORD record
ord-24f6e05dfe0d4901994054edd5814dd5
Source dataset
uspto-grants-2014_01
Patent number
US08629275B2

Reaction notes

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