Boron trifluoride → 2,2,3-Trimethyl-4-(3-oxo-1-cyclopenten-1-yloxy)-6-cyano-3-chromanol

HRID 2253707Notes

Reaction equation

HRID 2253707 reaction equation
[C:1]1(=[O:7])[CH2:5][CH2:4][C:3](=[O:6])[CH2:2]1.[H-].[Na+].[CH3:10][C:11]1([CH3:25])[C:20]2([CH3:22])[O:21][CH:19]2[C:18]2[C:13](=[CH:14][CH:15]=[C:16]([C:23]#[N:24])[CH:17]=2)[O:12]1.B(F)(F)F>C1COCC1>[CH3:10][C:11]1([CH3:25])[C:20]([CH3:22])([OH:21])[CH:19]([O:6][C:3]2[CH2:4][CH2:5][C:1](=[O:7])[CH:2]=2)[C:18]2[C:13](=[CH:14][CH:15]=[C:16]([C:23]#[N:24])[CH:17]=2)[O:12]1

Participants

6

Reactant 4

HCID 6356Boron trifluorideHCID 24758Sodium hydrideHCID 774661,3-CyclopentanedioneHCID 159254762,2,3-Trimethyl-3,4-epoxy-6-cyanochroman

Product 1

HCID 99487072,2,3-Trimethyl-4-(3-oxo-1-cyclopenten-1-yloxy)-6-cyano-3-chromanol

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

2.1 g of 1,3-cyclopentanedione are dissolved in 200 ml of THF under N2, 650 mg of NaH (80% in mineral oil) are added, the mixture is stirred for 1 hour, a solution of 4.6 g of 2,2,3-trimethyl-3,4-epoxy-6-cyanochroman ("IIa") in 20 ml of THF, then 2.4 ml of BF3 etherate are added successively and the mixture is stirred overnight at 20°. The mixture is evaporated and the 2,2,3-trimethyl-4-(3-oxo-1-cyclopenten-1-yloxy)-6-cyano-3-chromanol ("A") obtained is purified by chromatography on silica gel (ethyl acetate/methanol 100:1); m.p. 204°-206° (from isopropanol).

Workup

  1. stirringthe mixture is stirred overnight at 20°
  2. customThe mixture is evaporated

Sources & evidence

ORD record
ord-073fa3de2e894466a6f8965664874088
Source dataset
uspto-grants-1993_08
Patent number
US05232944

Reaction notes

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