α-Chloro β-oxo sulfenyl chlorides 2 were reduced by iodide ions to the corresponding α-oxo thioketones 3 which dimerized in situ in a hetero-[4 + 2] cycloaddition to give the 1,3,4- oxadithiin derivatives 4. The α-oxo thioketones 3, in situ, cyclized also with 2,3-dimethyl-1,3- butadiene to give the corresponding adducts 5 and only in case of the oxo thioketone intermediate 3d two products 4d and 5d were obtained. Also, The α-oxo thioketones 3a,c, underwent in situ, cycloaddition with furan to give the corresponding adducts 6a,c together with the corresponding thioketone dimers 4a,c. When this reaction was carried out in the presence of diethyl acetylenedicarboxylate or chalcone derivative 8, only the oxo thioketone dimers 4a-d were obtained.
α-
氯β-氧基
磺酰氯化物2被
碘离子还原为相应的α-氧基
硫酮3,在异[4 + 2]环加成中原位二聚形成1,3,4-氧
硫代
噻吩衍
生物4。α-氧基
硫酮3也在原位与
2,3-二甲基-1,3-丁二烯发生环化反应,形成相应的加合物5,仅在氧基
硫酮中间体3d的情况下得到两种产物4d和5d。此外,α-氧基
硫酮3a、c在原位与
呋喃发生环加成反应,形成相应的加合物6a、c以及相应的
硫酮二聚体4a、c。当在
乙酸二
乙酯乙炔二
羧酸酯或查尔康衍
生物8存在的情况下进行此反应时,仅得到氧基
硫酮二聚体4a-d。