Regiospecific hetero Diels-Alder synthesis of furo[2,3-g] and furo[3,2-g]quinoline-4,9-diones
作者:Omar Cherkaoui、Pascal Nebois、Houda Fillion、Monique Domard、Bernard Fenet
DOI:10.1016/0040-4020(96)00484-x
日期:1996.7
Diels-Alder reactions of 5- or 6-bromobenzofuran-4,7-diones 7 or 10 towards azadienes 1 afford regiospe-cifically furo[2,3-g] or furo[3,2-g]quinoline-4,9-diones 3 or 4. Assignment of the regioisomers, made by 2D NMR 1H-13H HMBC experiments, showed that the regiochemistry of the cycloadditions is under control of the bromine atom position. Calculations by the semiempirical method PM3 of the HOMO and
的5-或6-溴苯并呋喃-4,7-二酮的Diels-Alder反应7或10朝向azadienes 1得到regiospe-cifically呋喃并[2,3克]或呋喃并[3,2-克]喹啉-4,9-二二酮3或4。通过2D NMR 1 H- 13 H HMBC实验进行的区域异构体的分配表明,环加成物的区域化学在溴原子位置的控制下。由HOMO和azadienes的LUMO轨道系数的半经验方法PM3计算1和醌2表明,较大的位于在C-4 1和C-5为2。