Sách Selective Oxygenation and Plant-Growth Regulatory Activity of Sesquiterpene Lactones

Thảo luận trong 'Sách Ngoại Ngữ' bắt đầu bởi Thúy Viết Bài, 5/12/13.

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    Selective oxidation of alkenes to allylic alcohols, known as allylic oxidation, is an important transformation in organic chemistry. Several reagents are known1 to carry out this reaction, but selenium dioxide (SeO2) has been found to be a promising reagent. Some difficulties, such as the removal of colloidal selenium and the formation of organo-selenium by-products, have been circumvented by the Sharpless method,2 which uses catalytic SeO2 in combination with tert-butyl hydroperoxide (THBP). The allylic oxidation of terpenoids3–5 with the well-known reagent SeO2/TBHP/dichloromethane (CH2Cl2) has been published in reputable journals, but in our research, we have attempted to replace the use of TBHP by another oxidising agent: a urea hydrogen peroxide (UHP) complex. TBHP has several drawbacks; it is not safe to handle at higher concentrations, it is quite expensive, and it is not easily obtained.
     

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