本文之目的在研究利用醛類(aldehyde)經由自由基拔取醛基上之
氫原子後，進行α 脫去反應，脫去一分子一氧化碳(CO)後得到烷基
自由基，再與(E)-β-硝基苯乙烯((E)-β-nitrostyrene) 1a-1e，進行脫
去NO2 的自由基取代反應(substitution reaction)，來合成各種純反式
之幾何立體位向(E)-β-烷基-苯乙烯化合物。這個合成(E)-β-烷基-苯
乙烯衍生物的新方法是一個同時具有高化學選擇性及高位置選擇性
(high chemical-selectivity and high regio-selectivity)的反應。不但
脂肪族醛類(aliphatic aldehyde)適合當做反應物，而且芳香族醛類
(aromatic aldehyde)亦可應用在這個新穎的反應上。例如利用2-丙
烯醇-苯甲醛(2-allyloxy-benzaldehyde) 9 進行此反應時，當2-丙烯
醇-苯甲醛生成其相對應的苯甲醯基自由基(benzoyl radical)時，並不
會脫去一分子CO，而是直接進行分子內的加成到丙烯基的雙鍵上，
而生成3-cinnamyl-chroman-4-one 10。根據上述不同的反應特性可
以很明顯的區分出脂肪族醛類和芳香族醛類兩者的差異，而且利用芳
香族醛類這種特性， 可以很簡單地就合成出生物學上重要的
chromanone 化合物，上述反應結果已發表刊登於美國化學學會
(American Chemical Society)所出版之期刊雜誌The Journal of
Organic Chemistry (2004, 69, 3961)。

Various geometrically pure (E)- β-alkyl-styrenes have been
synthesized by the radical substitution of the NO2 group by the
alkyl moieties which were generated via hydrogen abstraction
followed by decarbonylation within aliphatic aldehydes. These
reactions occurred with high chemical- and regio-selectivity and
gave a new access to (E)- β-alkyl-styrenes. Not only aliphatic but
aromatic aldehydes can also be used in this novel reaction.
When 2-allyloxy-benzaldehyde 9 was used to perform this
reaction, the benzoyl radical added to the double bond directly
without decarbonylation and then 3-cinnamyl-chroman-4-one 10
was obtained. This special demarcation between aliphatic and
aromatic aldehydes was found to be a simple route to
biologically important chromanones. All these results have been
published in the Journal of Organic Chemistry (2004,69, 3961)

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