7-芳亚甲基异长叶烷酮类化合物的合成及其紫外吸收特征

Synthesis and ultraviolet absorption characteristics of 7-arylidene-isolongifolanene

以异长叶烷酮为原料,采用叔丁醇钾为催化剂,分别与对溴苯甲醛、对氟苯甲醛、间硝基苯甲醛、2,4-二氯苯甲醛等进行缩合反应,合成了系列7-芳亚甲基异长叶烷酮类化合物a—j。采用~1H NMR、^(13)C NMR、GC-MS和FT-IR等分析手段对合成所得7-芳亚甲基异长叶烷酮类化合物的结构进行了鉴定,并探索了化合物a—j的紫外吸收特性与光稳定性。结果表明:化合物a、b、c、d、j对中波紫外线(UVB)具有良好的吸收性能;而化合物e、f、g、h和i对长波紫外线(UVA)和UVB均具有较好的吸收性能。化合物a—j的光稳定顺序为h>g>e>c>a>d>b>f>i>j,其紫外线吸收强度顺序为d>i>e>h>g>f>b>c>j>a。

A series of 7-arylidene-isolongifolanone a--j were synthesized by condensation of isolongifolanone with aro- matic aldehydes including 4-bromobenzaldehyde, 4-fluorobenzaldehyde, 3-nitrobenzaldehyde, 2,4-dichlorobenzaldehyde under catalyzation of potassium tert-butoxide. The structures of compounds a--J were identified by means of 1H NMR, 13C NMR, GC-MS and FT-IR, and their ultraviolet absorption characteristics as well as light stabilities were also investi- gated. The results showed that compounds a, b, c, d and j exhibited good absorbency as the medium-wave ultraviolet （UVB） type absorbents,and compounds e, f, g, h and i had both functions as long-wave ultraviolet （UVA） and UVB absorbents. The light stability sequence of those compounds was h〉g〉e〉c〉a〉d〉b〉f〉i〉j. The UV absorption intensity was d〉i〉e〉h〉g〉f〉b〉c〉j〉a.