In this study, the synthesis and characterization of novel indanone-based spiro-dihydrobenzofuran derivatives were examined. Firstly, chalcone-like compounds 4a-k, ($E)$-2-benzylidene-2,3-dihydro-1$H$-inden-1-one derivatives, were synthesized by the base-catalyzed addition of benzaldehyde derivatives to 2,3-dihydro-1$H$-inden-1-one. Then Mn(OAc)$_3}$-mediated addition of dimedone (2) to the chalcone-like compounds gave two novel spiro-dihydrobenzofuran isomers: (3$S)$-6,6-dimethyl-3-aryl-6,7-dihydro-3$H$-spiro [benzofuran-2,2'-indene]-1',4(3'$H$,5$H)$-dione (5a-k) and (2'$S)$-6,6-dimethyl-2-aryl-6,7-dihydro-2$H$-spiro[benzofuran-3,2'-indene]-1',4(3'$H$,5$H)$-dione (6a-k) in good yields. The isomers were separated by column chromatography and their structures were elucidated on the basis of spectral data (NMR, IR) and elemental analysis.
本研究考察了新型
茚酮基螺二氢
苯并呋喃衍
生物的合成和表征。首先,通过
苯甲醛衍
生物与 2,3-二氢-1$H$-
茚-1-酮的碱催化加成,合成了类
查耳酮化合物 4a-k,即 ($E)$-2-亚苄基-2,3-二氢-1$H$-
茚-1-酮衍
生物。然后,Mn(OAc)$_3}$ 介导的二酮 (2) 与类
查耳酮化合物的加成反应得到了两种新型螺二氢
苯并呋喃异构体: (3$S)$-6,6-dimethyl-3-aryl-6,7-dihydro-3$H$-spiro [benzofuran-2,2'-indene]-1',4(3'$H$,5$H)$-dione (5a-k) 和 (2'$S)$-6、6,7-二氢-2$H$螺[
苯并呋喃-3,2'-
茚]-1',4(3'$H$,5$H)$二酮 (6a-k)。通过柱色谱法分离了这些异构体,并根据光谱数据(核磁共振、红外)和元素分析阐明了它们的结构。