Triethylsilane → ethyl 2-ethyl-4-(tetrahydro-2H-pyran-4-yloxy)cyclopentanecarboxylate

HRID 1969806Notes

Reaction equation

HRID 1969806 reaction equation
[Si]([O:8][CH:9]1[CH2:13][CH:12]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH:11]([CH2:19][CH3:20])[CH2:10]1)(C(C)(C)C)(C)C.C([SiH](CC)CC)C.[O:28]1[CH2:33][CH2:32][C:31](=O)[CH2:30][CH2:29]1>CC#N.[Bi](Br)(Br)Br>[CH2:19]([CH:11]1[CH2:10][CH:9]([O:8][CH:31]2[CH2:32][CH2:33][O:28][CH2:29][CH2:30]2)[CH2:13][CH:12]1[C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH3:20]

Participants

6

Reactant 3

HCID 12052Triethylsilane2×HCID 121599Tetrahydro-4H-pyran-4-one2×HCID 58557197Ethyl 4-(tert-butyldimethylsilyloxy)-2-ethylcyclopentanecarboxylate2×

Product 1

HCID 58557583ethyl 2-ethyl-4-(tetrahydro-2H-pyran-4-yloxy)cyclopentanecarboxylateYield 281%

Reagents, catalysts & solvents 2

HCID 82232bismuth(III) bromideCatalyst2×HCID 6342AcetonitrileSolvent2×

Procedure

To a solution of ethyl 4-(tert-butyldimethylsilyloxy)-2-ethylcyclopentanecarboxylate (0.100 g, 0.333 mmol) in MeCN (2.2 mL) was added triethylsilane (0.080 mL, 0.499 mmol) and bismuth(III) bromide (0.010 g, 0.022 mmol). The reaction mixture was stirred at ambient temperature for about 1 min followed by dropwise addition of dihydro-2H-pyran-4(3H)-one (0.050 g, 0.499 mmol). The reaction mixture was stirred at ambient temperature for about 15 min. The reaction was filtered through an Acrodisc® and the solvent was removed under reduced pressure. To a solution of ethyl 4-(tert-butyldimethylsilyloxy)-2-ethylcyclopentanecarboxylate (0.200 g, 0.666 mmol) in MeCN (4.5 mL) was added triethylsilane (0.160 mL, 1.00 mmol) and bismuth(III) bromide (0.020 g, 0.045 mmol). The reaction mixture was stirred at ambient temperature for about 1 min followed by dropwise addition of dihydro-2H-pyran-4(3H)-one (0.100 g, 0.998 mmol). The reaction mixture was stirred at ambient temperature for about 15 min. The reaction was filtered through an Acrodisc® and the solvent was removed under reduced pressure. The residues were dissolved in DCM (2 mL) each, combined, and the crude material was purified by silica gel chromatography using a gradient of 10-100% EtOAc in heptane to give ethyl 2-ethyl-4-(tetrahydro-2H-pyran-4-yloxy)cyclopentanecarboxylate (0.253 g, 98%) as a colorless oil; 1H NMR (400 MHz, CDCl3) δ 4.13 (q, J=7.1, 2H), 4.05-3.98 (m, 1H), 3.98-3.88 (m, 2H), 3.58-3.47 (m, 1H), 3.46-3.36 (m, 2H), 2.80 (q, J=8.5, 1H), 2.16 (dt, J=13.3, 7.7, 1H), 2.09-1.93 (m, 3H), 1.90-1.81 (m, 2H), 1.62-1.49 (m, 3H), 1.43 (ddd, J=11.1, 7.4, 5.2, 1H), 1.33-1.22 (m, 4H), 0.92-0.83 (m, 3H).

Workup

  1. stirringThe reaction mixture was stirred at ambient temperature for about 15 min
  2. filtrationThe reaction was filtered through an Acrodisc®
  3. customthe solvent was removed under reduced pressure
  4. stirringThe reaction mixture was stirred at ambient temperature for about 1 min
  5. stirringThe reaction mixture was stirred at ambient temperature for about 15 min
  6. filtrationThe reaction was filtered through an Acrodisc®
  7. customthe solvent was removed under reduced pressure
  8. dissolutionThe residues were dissolved in DCM (2 mL) each,
  9. customthe crude material was purified by silica gel chromatography

Sources & evidence

ORD record
ord-3b46a8dd1fac4a10b3df2f4fe67fb3d6
Source dataset
uspto-grants-2013_04
Patent number
US08426411B2

Reaction notes

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