Reaction #1244248

Reaction equation

14

5,7,8-Trimethoxy-1,4-dihydro-1,4-methanonaphthalene-6-carboxylic acid methyl ester

NaOH

→

15

Yield 100.1%

5,7,8-Trimethoxy-1,4-dihydro-1,4-methanonaphthalene-6-carboxylic acid

Yield 100.1%

Solvents

methanol

Conditions

Workup

1. 1
   Otherthe resulting reaction mixture
2. 2
   Temperaturewas heated
3. 3
   Temperatureat reflux for 5 h
4. 4
   OtherMethanol was removed under reduced pressure
5. 5
   workup.ADDITIONa 3 N HCl solution was added
6. 6
   ExtractionThe reaction mixture was extracted three times with ethyl acetate
7. 7
   Dryingdried over sodium sulfate
8. 8
   Concentrationconcentrated under reduced pressure

Procedure

To a solution of 14 (0.591 g, 2.05 mmol) in methanol (50 mL) was added a 4 N NaOH solution (50 mL), and the resulting reaction mixture was heated at reflux for 5 h. Methanol was removed under reduced pressure and a 3 N HCl solution was added to achieve pH 1. The reaction mixture was extracted three times with ethyl acetate, dried over sodium sulfate, and concentrated under reduced pressure to yield 0.567 g of 15 as a brown oil in nearly quantitative yield. 1H NMR (300 MHz, CDCl3): δ=2.18-2.27 (m, 2H, CH2), 3.86 (s, 3H, O—CH3), 3.89 (s, 3H, O—CH3), 3.92 (s, 3H, O—CH3), 4.19-4.22 (m, 2H, CH—CH(C)—CH2), 6.78-6.86 (m, 2H, HC═CH); 13C NMR (75 MHz, CDCl3): δ=47.6 (CH—CH(C)—CH2), 47.9 (CH—CH(C)—CH2), 61.6 (CH3), 62.1 (CH3), 62.5 (CH3), 68.5 (CH2), 117.9, 137.8, 142.4 (HC═CH), 142.9 (HC═CH), 144.2, 147.2, 147.6, 148.6, 170.6; ESI-MS calcd for C15H16O5 [M−H]−: 275.0920. found 275.0910.

Source