反应详情

2.7 g (71 mmols) lithium aluminium hydride were added to a suspension of 2.7 g (24 mmols) aluminium chloride partially dissolved in 120 ml 1,2-dimethoxyethane, the addition of lithium aluminium hydride causing a rise in temperature to 50° C. The resulting slurry was incubated at 50° C. for 30 minutes. A solution of 6.8 g (23 mmols) 1-(4-chlorobenzyl)-1,2-epoxy-3,3-dimethyl-2-methoxycarbonylcyclopentane prepared as described in (g) in 30 ml 1,2-dimethoxyethane was then added over a period of 30 minutes whilst maintaining the temperature of the reaction mixture at 50°-55° C. After 1 hour, thin layer chromatography indicated that the reaction was complete and the excess lithium aluminium hydride was therefore destroyed by adding 10 ml saturated aqueous ammonium chloride solution followed by 10 ml water. This produced a sludgy solid which filtered only slowly. After filtration, the solid was dissolved in 2N hydrochloric acid and extracted twice with diethyl ether. The extracts were combined with the filtrate and flashed to give 5.9 g crude product. Trituration with cold 60/80 petroleum and a little diethyl ether gave 5.45 g 1-(4-chlorobenzyl)-3,3-dimethyl-2-hydroxy-2-hydroxymethylcyclopentane as a white solid, m.pt. 103°-104° C. Yield: 82%.

1. additionwas then added over a period of 30 minutes
2. temperaturewhilst maintaining the temperature of the reaction mixture at 50°-55° C
3. waitAfter 1 hour
4. customthe excess lithium aluminium hydride was therefore destroyed
5. additionby adding 10 ml saturated aqueous ammonium chloride solution
6. customThis produced a sludgy solid which
7. filtrationfiltered only slowly
8. filtrationAfter filtration
9. dissolutionthe solid was dissolved in 2N hydrochloric acid
10. extractionextracted twice with diethyl ether
11. customto give 5.9 g crude product