Tetrahydrofuran → 4-(2,2,3-Trimethyl-3-cyclopenten-1-yl)-2-butenoic acid

Temperature

83 °C

Ethyl 4-(2,2,3-trimethylcyclopent-3-enyl)but-2-enoate (2.0 g, 9.0 mmol) was added to THF (10 ml) in a 50 ml round bottom flask. Aqueous 1 N NaOH (10 ml) was then added to the flask and the reaction mixture was refluxed at 83° C. for 19 h. Upon completion of the reaction, the reaction mixture was diluted with 1 N NaOH (10 ml) and the aqueous layer was washed twice with MTBE (10 ml×2). The aqueous layer was treated with aqueous 1.0 N HCl until it reached a pH of about 3 (for example from 2 to 4), then extracted three times with AcOEt (10 ml×3). The combined AcOEt extracts were concentrated in vacuo and purified via flash column chromatography with MTBE/Hexanes (5-20% gradient) to give 4-(2,2,3-trimethylcyclopent-3-enyl)but-2-enoic acid (1.58 g) as a viscous oil (1.58 g, 90%). The NMR data is indicated below.

1. customUpon completion of the reaction
2. washthe aqueous layer was washed twice with MTBE (10 ml×2)
3. additionThe aqueous layer was treated with aqueous 1.0 N HCl until it
4. extractionextracted three times with AcOEt (10 ml×3)
5. concentrationThe combined AcOEt extracts were concentrated in vacuo
6. custompurified via flash column chromatography with MTBE/Hexanes (5-20% gradient)

ORD record

ord-e9d25c05476e49178d052078d14631c1

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08409649B2