| Budget Amount *help |
¥4,600,000 (Direct Cost: ¥4,600,000)
Fiscal Year 1985: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1984: ¥3,600,000 (Direct Cost: ¥3,600,000)
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| Research Abstract |
Diisobutylaluminum hydride (DIBAH) is a widely employed reducing reagent, which reacts with <alpha> , <beta> -unsaturated carbonyl compounds to produce allylic alcohols. We have found that the hexamethylphosphoric triamide (HMPA) ligand changes the reducing reactivity of DIBAH to effect the conjugate reduction of <alpha> , <beta> -unsaturated carbonyl compounds without the carbonyl reduction and the methylcopper-catalyst enhances the reactivity of the conjugate reduction by DIBAH-HMPA. The selective and efficient conjugate reduction of a variety of <alpha> , <beta> -unsaturated carbonyl compounds (aldehydes ketones, and esters) can be accomplished by MeCu-DIBAH-HMPA.
The MeCu-DIBAH-HMPA system effects the stereoselective trans conjugate reduction of progesterone and angularly methylated hydrindenone. The latter reduction provides a convenient method of preparing angularly methylated trans fused hydrindane ring. The kind of the copper compound controles the stereoselectivity of the conjugate reduction, and the HCu-DIBAH-HMPA system gives predominantly the cis fused hydrindanone. The <alpha> , <beta> -reduction of <alpha> , <beta> -unsaturated nitriles can be effected by the MeCu-DIBAH system without HMPA.
Thus, we have been able to develope a novel, chemo- and stereoselective reducing reagent of MeCu-DIBAH-HMPA which is useful in organic synthesis.
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