反应详情

Potassium hydroxide (8 g, 87% weight pure, 0.12 mol) was dissolved in 7:1 water-EtOH (80 mL) to give a 1.56M solution. A suspension of 2-butyl-5-methoxy-(2-oxopropyl)-1-indanone (83 mg, 0.3 mmol) in 5 mL of the KOH solution was stirred and heated at reflux for 23 hours. After cooling, the mixture was diluted with water (10 mL) and extracted with EtOAc (3×30 mL). The extracts were washed with 1N HCl, water, and brine (20 mL each), dried over MgSO4, filtered, and concentrated under vacuum to an oil. 1H NMR revealed a 65:35 mixture of desired product to starting material. The mixture was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate (Analtech, Newark, Del.), developing twice with 5:1 hexane-EtOAc. The product band was extracted with EtOAc and the extracts evaporated under vacuum to provide 8a-butyl-6-methoxy-8,8a-dihydrocyclopenta[a]inden-2(1H)-one as an oil.

1. temperatureheated
2. temperatureat reflux for 23 hours
3. temperatureAfter cooling
4. extractionextracted with EtOAc (3×30 mL)
5. washThe extracts were washed with 1N HCl, water, and brine (20 mL each)
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated under vacuum to an oil
9. additiona 65:35 mixture of desired product
10. customThe mixture was purified by preparative layer chromatography on a 0.1×20×20 cm silica gel GF plate (Analtech, Newark, Del.)
11. extractionThe product band was extracted with EtOAc
12. customthe extracts evaporated under vacuum