Hexahydrophthalic anhydride, cis- → (3Ar,7as)-hexahydro-2-benzofuran-1(3h)-one

With stirring and ice-cooling, 80 ml of a solution of cis-cyclohexane-1,2-dicarboxylic anhydride (15.4 g, 100 mmol) in THF are added over a period of 10 min to a mixture of sodium borohydride (3.8 g, 100 mmol) in 20 ml of THF. The ice-bath is removed and the mixture is stirred for 2 h. 40 ml of 6 N hydrochloric acid are added carefully and the mixture is concentrated. 200 ml of water are added and the aqueous phase is extracted with ether. The organic phase is dried, filtered, concentrated and distilled under reduced pressure (123° C., 13 mm; 75° C., 0.5 mm).

1. temperatureice-cooling
2. customThe ice-bath is removed
3. stirringthe mixture is stirred for 2 h
4. addition40 ml of 6 N hydrochloric acid are added carefully
5. concentrationthe mixture is concentrated
6. addition200 ml of water are added
7. extractionthe aqueous phase is extracted with ether
8. customThe organic phase is dried
9. filtrationfiltered
10. concentrationconcentrated
11. distillationdistilled under reduced pressure (123° C., 13 mm; 75° C., 0.5 mm)

ORD record

ord-ddfeca8bc4d84471982f76def8558cc8

Source dataset

uspto-grants-2002_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06376539B1