Reacción #487533

Ecuación de reacción

triethylamine

2-hydroxyhexanoic acid

2-bromopropionyl bromide

→

3-Methyl-6-butyl-1,4-dioxane-2,5-dione

Rendimiento 40.0%

Disolventes

acetone

Condiciones de reacción

Tratamiento posterior

1. 1
   FiltraciónAfter filtration of the triethylammonium bromide salts, acetone
2. 2
   workup.DISTILLATIONwas distilled off
3. 3
   workup.DISSOLUTIONthe resulting mixture was dissolved in 300 mL ethyl acetate
4. 4
   FiltraciónAfter filtration over silica gel the solvents
5. 5
   workup.DISTILLATIONwere distilled off
6. 6
   Otrothe remaining crude product was recrystallized from hexane

Procedimiento

2.5 g 2-hydroxyhexanoic acid (18.9 mmol) and 2.1 mL 2-bromopropionyl bromide (19.7 mmol) were stirred at 75° C. under nitrogen for 12 h. 150 mL acetone and 5.3 mL anhydrous triethylamine (38 mmol) were added to the mixture and the solution was stirred for 3 h at 60° C. After filtration of the triethylammonium bromide salts, acetone was distilled off and the resulting mixture was dissolved in 300 mL ethyl acetate:hexane mixture (1:2). After filtration over silica gel the solvents were distilled off, and the remaining crude product was recrystallized from hexane. 1H NMR (500 MHz, CDCl3): δ 5.05 (q, 1H), 4.90 (dd, 1H), 1.9-2.15 (br m, 2H), 1.68 (d), 1.65 (d), (3H, of 2 diastereoisomers), 1.3-1.6 (br m, 4H), 0.93 (t, 3H). 13C NMR (500 MHz, CDCl3): δ 167.54, 166.93, 166.25, 165.85, 75.79, 72.50, 72.24, 31.61, 29.70, 26.69, 26.42, 22.19, 21.97, 17.52, 15.81, 13.72, 13.66. ELEM. ANAL. Calcd. for C9H14O4: C, 58.06; H, 7.53. Found: C, 57.62; H, 7.60. Yield: 40%.

Fuente