Tetrahydrofuran → tert-Butyl (5S,7S)-1-oxo-2-oxaspiro[4.4]non-8-en-7-ylcarbamate

HRID 1747143Notes

Reaction equation

HRID 1747143 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]1[CH2:13][C@@:12]([CH2:18][CH2:19][O:20][Si](C(C)(C)C)(C)C)([C:14]([O:16]C)=O)[CH:11]=[CH:10]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C1COCC1.CCCC[N+](CCCC)(CCCC)CCCC.[F-]>CCOC(C)=O>[O:16]=[C:14]1[C@:12]2([CH:11]=[CH:10][C@@H:9]([NH:8][C:6](=[O:7])[O:5][C:1]([CH3:2])([CH3:3])[CH3:4])[CH2:13]2)[CH2:18][CH2:19][O:20]1

Participants

5

Reactant 3

HCID 8028TetrahydrofuranHCID 2724141Tetrabutylammonium FluorideHCID 86708127(1S,4S)-methyl 4-(tert-butoxycarbonylamino)-1-(2-(tert-butyldimethylsilyloxy)ethyl)cyclopent-2-enecarboxylate

Product 1

HCID 86708140tert-Butyl (5S,7S)-1-oxo-2-oxaspiro[4.4]non-8-en-7-ylcarbamate

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

To a solution of the product of Step D (1149 g, 2.875 mol) and THF (5.75 L) was added TBAF (1M in THF, 2.875 L) over ˜1 h. The reaction was stirred for 1 h at rt, and diluted with EtOAc. The organic layer was washed with brine, diluted with heptanes and the organic layer was further washed with water and brine. The organic layer was evaporated, the crystallized product was filtered, and washed with heptanes to provide the product of Step E as a white solid. 1H NMR (400 MHz, CHLOROFORM-d) d=5.86-5.98 (m, 3H), 5.67 (d, J=5.4 Hz, 3H), 5.03-5.20 (m, 2H), 4.76-4.87 (m, 3H), 4.28 (t, J=7.0 Hz, 5H), 2.08-2.31 (m, 8H), 1.99 (d, J=2.4 Hz, 3H), 1.34 (s, 25H).

Workup

  1. washThe organic layer was washed with brine
  2. additiondiluted with heptanes
  3. washthe organic layer was further washed with water and brine
  4. customThe organic layer was evaporated
  5. filtrationthe crystallized product was filtered
  6. washwashed with heptanes

Sources & evidence

ORD record
ord-e92d891a87b94cb4ae110db654fa821b
Source dataset
uspto-grants-2015_10
Patent number
US09150532B2

Reaction notes

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