Sulfuric Acid → 1-Methyl-6-oxabicyclo[3.2.1]octan-7-one

Temperatur

0 °C

A solution of 1-methyl-3-cyclohexenecarboxylic acid (47 g) in chloroform (200 ml) was cooled to -5° C. Then, a mixture of conc. H2SO4 (100 ml) and chloroform (100 ml) was added. After stirring at 0° C. for 15 minutes, the mixture was poured onto ice (500 g) and extracted with chloroform. The chloroform layer was washed in sequence with water, saturated aqueous sodium hydrogen carbonate solution and water, and dried (MgSO4), and the chloroform was distilled off. The residual oily substance was subjected to column chromatography using silica gel (500 g) and eluted with ether-hexane (1:3 v/v). From the first eluate fractions, crystals of 1-methylcyclohexane-1,3-carbolactone (28.0 g, 59.6% yield) were recovered and recrystallized from hexane. m.p. 37°-38° C.

1. additionwas added
2. additionthe mixture was poured onto ice (500 g)
3. extractionextracted with chloroform
4. washThe chloroform layer was washed in sequence with water, saturated aqueous sodium hydrogen carbonate solution and water
5. dry with materialdried (MgSO4)
6. distillationthe chloroform was distilled off
7. washeluted with ether-hexane (1:3 v/v)

ORD-Eintrag

ord-fd567031eb5c458cabb3aa63998416eb

Quelldatensatz

uspto-grants-1984_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04461902