A Cyclization Approach toward Five-Membered Heteroaromatic<i>o</i>-Quinodimethanes<i>via</i>Fused-3-Sulfolenes
                                
                                    
                                        作者:Ta-Shue Chou、Chung-Ying Tsai、Shwu-Jiuan Lee                                    
                                    
                                        DOI:10.1002/jccs.199700045
                                    
                                    
                                        日期:1997.6
                                    
                                    AbstractA general strategy involving the zincation of 4‐bromo‐3‐chloro‐2‐sulfolene, in situ condensation with an α‐heterosubstituted acetaldehyde, and subsequent cyclization reaction as the key steps toward the synthesis of furano‐ and thieno‐3‐sulfolenes is described. These fused‐3‐sulfolenes are demonstrated to be good precursors for the corresponding o‐quinodimethanes.