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本文指出癸硼氢可以作为一种新的硼氢化试剂;它与烯烃在四氢呋喃中反应,然后经碱性过氧化氢氧化水解,可获得正常的硼氢化产物.即自莰烯可获得内异莰醇和外异茨醛,自Δ~2-胆甾烯获得3α-,2α-和3β-胆甾醇的混合物,自Δ~5-胆甾烯获得6α-胆甾醇和6α-胆甾酮;癸硼氢也可将3-胆甾酮还原为3β和3α-胆甾醇的混合物.据反应进行情况以及产品的结构,证明癸硼氢的硼氢化反应亦是通过顺式加成的机制,并且从双键位阻较小的一面进行反应.在Δ~5-胆甾烯的硼氢化反应中,癸硼氢的反应性较乙硼氢差,空间效应可能是这种差别的原因之一.莰烯、Δ~2-胆甾烯及3-胆甾酮与癸硼氢的反应的分子比分别为2. 3至2. 5∶1;1. 5∶1和6至7∶1.
This paper indicates that decabromohydrin can be used as a new borohydride reagent; it reacts with olefins in tetrahydrofuran and then is oxidized and hydrolyzed by alkaline hydrogen peroxide to obtain the normal hydroboration product. Cholesterol and a mixture of 3? -, 2? - and 3? -cholesterol from? 2-cholestene, 6? -cholesterol and 6? -cholesterone from ?? - Hydrogen can also reduce 3-Cholesterol to a mixture of 3β and 3α-Cholesterol.According to the progress of the reaction and the structure of the product, the hydroboration reaction of decabromohydrin is also confirmed by the cis-addition mechanism, The key side of the resistance of the smaller side of the reaction in the Δ ~ 5-cholestene hydroboration, decabromohydrogen reactivity than the B-borohydrogen, space effect may be one of the reasons for this difference. Camphene , The molecular ratio of Δ2-cholestenol and the reaction of 3-cholesterone and decabromohydrin was 2.3 to 2.5: 1, 1.5: 1 and 6 to 7: 1, respectively.