Reaction #631990

Reaction equation

HCl

3-hydroxy-1-(2,6,6-trimethyl-3-cyclohexen-1-yl)-1-butanone

pyridine

ethyl chloroformate

→

Ethyl 1-methyl-3-oxo-3-(2,6,6-trimethyl-3-cyclohexen-1-yl)propyl Carbonate

Conditions

Workup

1. 1
   Extractionextracted twice with ether
2. 2
   Washwashed (H2O, saturated aqueous NaHCO3
3. 3
   Dryingbrine), dried over Na2SO4
4. 4
   Concentrationconcentrated
5. 5
   OtherThe oil (2.38 g) was purified by flash-chromatography (cyclohexane/AcOEt=98:2)

Procedure

A solution of 3-hydroxy-1-(2,6,6-trimethyl-3-cyclohexen-1-yl)-1-butanone (8.0 mmol) in pyridine (1.85 g, 23.4 mmol) was treated at 0° C. with ethyl chloroformate (1.24 g, 23.4 mmol). The reaction solution was stirred at room temperature for 36 hours, treated with 5% aqueous HCl and extracted twice with ether, washed (H2O, saturated aqueous NaHCO3, then brine), dried over Na2SO4 and concentrated. The oil (2.38 g) was purified by flash-chromatography (cyclohexane/AcOEt=98:2), using SiO2 (100 g). Yield: 2.06 g (78%).

Source