Reaction #1121756

Reaction equation

2-Hydroxycarbonylmethyl-4-tetrahydropyranyloxy-2-cyclopenten-1-one

2-naphthol

1,3-dicyclohexylcarbodiimide

→

title compound

2-(2-Naphthyloxycarbonylmethyl)-4-hydroxy-2-cyclopenten-1-one

Solvents

dichloromethane

dichloromethane

Conditions

Workup

1. 1
   FiltrationThe precipitate was filtered off
2. 2
   WashThe filtrate was washed with 20 ml of diluted hydrochloride solution, water
3. 3
   Dryingdried over anhydrous magnesium sulfate
4. 4
   Filtrationfiltered
5. 5
   Otherevaporated under vacuum
6. 6
   workup.DISSOLUTIONThe crude product was dissolved in 30 ml acetone
7. 7
   workup.ADDITION6 ml water, further added with 0.3 g p-toluenesulfonic acid
8. 8
   workup.STIRRINGstirred overnight
9. 9
   OtherUpon completion of the reaction, acetone
10. 10
    Otherwas evaporated
11. 11
    workup.ADDITIONthe reaction mixture was diluted with ethyl acetate
12. 12
    Washwashed with an aqueous sodium bicarbonate solution
13. 13
    Filtrationdehydration, filtration, and evaporation, and purification by chromatography on silica gel

Procedure

5 g of 2-Hydroxycarbonylmethyl-4-tetrahydropyranyloxy-2-cyclopenten-1-one (21 mmol) obtained from Example 5, 2-naphthol (4.7 g, 32 mmol), dichloromethane (50 ml), and 0.2 g 4-(dimethylamine)pyridine were added together to a 50 ml dichloromethane solution containing 1,3-dicyclohexylcarbodiimide (7 g, 34 mmol). The reaction mixture was stirred at room temperature for about 4 hours. The precipitate was filtered off. The filtrate was washed with 20 ml of diluted hydrochloride solution, water, dried over anhydrous magnesium sulfate, filtered, and evaporated under vacuum. The crude product was dissolved in 30 ml acetone and 6 ml water, further added with 0.3 g p-toluenesulfonic acid and stirred overnight. Upon completion of the reaction, acetone was evaporated and the reaction mixture was diluted with ethyl acetate and washed with an aqueous sodium bicarbonate solution and a brine solution. The organic liquid was subjected to the previous work-up procedure, including dehydration, filtration, and evaporation, and purification by chromatography on silica gel to obtain the title compound as white solid. MP: 81° C. (4.2 g, 71%) 1H-NMR (CDCl3/TMS): δ 7.82 (m,2H), 7.78 (d, 1H), 7.55 (m,2H), 7.46 (m,2H), 7.21 (dd, 1H), 5.04 (m, 1H), 3.56 (s, 2H), 2.89 (dd, 1H), 2.38 (dd, 1H), 1.60 (brs, 1H).

Source