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Synlett 1997; 1997(12): 1465-1466
DOI: 10.1055/s-1997-1077
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Reexamination of Diisobutylaluminum Hydride as a Stereoselective Reducing Agent for Reduction of Cyclic Ketones to Thermodynamically More Stable Alcohols

Jin Soon Cha1 , Oh Oun Kwon, Jong Mi Kim, Sung Dong Cho2
  • 1Department of Chemistry, Yeungnam University, Kyongsan 712-749, Republic of Korea
  • 2Department of Chemistry, Chosun University, Kwangju 501-759, Republic of Korea
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Publication History

Publication Date:
31 December 2000 (online)

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The reducing property of diisobutylaluminum hydride (DIBAH) has been reexamined as a stereoselective reducing agent for reduction of representative cyclic ketones. When the reduction of excess cyclic ketone with DIBAH was carried out at 0 °C in ethyl ether, only 1 equiv of the free hydride was involved to show a low stereoselectivity. However, when performed at 25 °C or under reflux in ethyl ether, one isobutyl group as well as the free hydride was also involved in this reduction: the first equiv of ketone was reduced rapidly and the second one reduced, in a relatively slow rate. In addition, the stereoselectivity increases consistently with increase of reaction time to afford the thermodynamically more stable isomer alcohols exclusively.

diisobutylaluminum hydride - stereoselective reduction - cyclic ketones