4-(6,7-Dimethyl-2-naphthyl)butanoic acid → 6,7-Dimethyl-4-oxo-1,2,3,4-tetrahydrophenanthrene

HRID 1488328Notes

Reaction equation

HRID 1488328 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][C:11]=1[CH3:12])[CH:8]=[C:7]([CH2:13][CH2:14][CH2:15][C:16]([OH:18])=O)[CH:6]=[CH:5]2>CS(O)(=O)=O>[CH3:12][C:11]1[CH:10]=[C:9]2[C:4](=[CH:3][C:2]=1[CH3:1])[CH:5]=[CH:6][C:7]1[CH2:13][CH2:14][CH2:15][C:16](=[O:18])[C:8]2=1

Participants

3

Reactant 1

HCID 229045924-(6,7-Dimethyl-2-naphthyl)butanoic acid

Product 1

HCID 229045956,7-Dimethyl-4-oxo-1,2,3,4-tetrahydrophenanthrene

Reagents, catalysts & solvents 1

HCID 6395Methanesulfonic AcidSolvent

Conditions

Temperature
90 °C

Procedure

4-(6,7-Dimethyl-2-naphthyl)butanoic acid (6.21 g, 0.026 mole) was added to 40 ml of CH3SO3H. The mixture was heated to 90° C. until all solid material disappeared (about 30 min.). The mixture was poured into ice and then extracted twice with ethylacetate. Combined ethylacetate solution was dried over anhydrous Na2SO4 and then concentrated. After flash chromatography on silica gel, 6,7-Dimethyl-4-oxo-1,2,3,4-tetrahydrophenanthrene was obtained as a pale yellow solid material (4.96 g, 0.022 mole, 85% yield). mp 114.0°-115.0° C., 1H NMR (CDCl3) δ 2.12-2.20 (m, 2H), 2.41 (s, 3H), 2.47 (s, 3H), 2.77 (t, J=6.4 Hz, 2H), 3.09 (t, J=6.4 Hz, 2H), 7.21 (d, J=8.3 Hz, 1H), 7.54 (s, 1H), 7.31 (d, J=8.3 Hz, 1H), 9.20 (s, 1H), IR (KBr) cm-1 2930, 1669, 1590, 1510, Anal. Calcd. for C16H16O: C, 85.67; H, 7.19. Found: C, 86.00; H, 7.18.

Workup

  1. custom(about 30 min.)
  2. additionThe mixture was poured into ice
  3. extractionextracted twice with ethylacetate
  4. dry with materialCombined ethylacetate solution was dried over anhydrous Na2SO4
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-522198d38f8b470bbd441427ff4c9ea2
Source dataset
uspto-grants-1997_10
Patent number
US05674387

Reaction notes

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