Triethylamine → 1,2a,4,5,6,6a,7,7a-Octahydrocyclobuta[a]inden-2-one

HRID 2275995

Reaction equation

HRID 2275995 reaction equation
[CH2:1]([CH:4]1[CH2:9][CH2:8][CH2:7][CH2:6][C:5]1=[CH:10][C:11]([OH:13])=O)[CH:2]=[CH2:3].C(N(CC)CC)C>ClCCl>[CH2:3]1[CH:2]2[CH2:1][CH:4]3[C:5]([CH:10]2[C:11]1=[O:13])=[CH:6][CH2:7][CH2:8][CH2:9]3

Participants

4

Reactant 2

HCID 8471TriethylamineHCID 2785322-(2-Allylcyclohexylidene)acetic acid

Product 1

HCID 139474001,2a,4,5,6,6a,7,7a-Octahydrocyclobuta[a]inden-2-oneYield 83.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 2-(2-allylcyclohexylidene)acetic acid (800 mg, 4.44 mmol) in dichloromethane (200 mL) was added Ghosez reagent (5.77 mmol, 0.795 mL) at room temperature. The solution was stirred for 45 min until the acid chloride was formed. Then N,N-dimethylaminopyridine (55 mg, 0.45 mmol) was added and the solution was heated to reflux. A solution of triethylamine (8.9 mmol, 1.25 mL) in dichloromethane (3.75 mL) was added dropwise over 30 min. The solution was refluxed for another 1 h and solvent was distilled off. Purification by flash chromatography (pentane/Et2O 95/5) gave 1,2a,4,5,6,6a,7,7a-octahydrocyclobuta[a]inden-2-one (600 mg, 83%) as a colourless liquid, with 20% of the tetrasubstituted regioisomere. 1H NMR (400 MHz, CDCl3) 5.59 (1H, brs), 3.92 (1H, brs), 3.21 (1H, dddd), 2.92 (1H, m), 2.73 (1H, m), 2.51 (1H, m), 2.04 (4H, m), 1.79 (1H, m), 1.48 (2H, m), 1.05 (1H, m).

Workup

  1. customwas formed
  2. temperaturethe solution was heated to reflux
  3. temperatureThe solution was refluxed for another 1 h
  4. distillationsolvent was distilled off
  5. customPurification by flash chromatography (pentane/Et2O 95/5)

Sources & evidence

ORD record
ord-2d33d8b10de54dcb9df9bf62cac0c033
Source dataset
uspto-grants-2015_09
Patent number
US09131688B2

Linked notes

Loading…