Chemistry of ethanediyl S,S-acetals 6- An example of vicarious nucleophilic substitution of hydrogen in 1,4-benzodithians
摘要:
1,4-Benzodithians, when treated with bromine in anhydrous chloroform, undergo very fast monobromination at the aromatic ring. By the use of quantum mechanical semiempirical calculations, the reaction is shown to proceed most likely via a vicarious nucleophilic substitution of hydrogen.
synthetic way leading to 1,4-benzodithians (2) variously substituted at the benzenoid ring. The ready availability of these latter makes the 1,4-benzodithian system itself being regarded as appealing intermediate to obtain, after sulfur replacement or removal, aromatic compounds that cannot be prepared under the usual electrophilicsubstitution conditions.
A new route to 2,3-dihydro-1,4-benzoxathiine and 2,3-dihydro-1,4-benzodithiine
作者:James Y. Satoh、Amos M. Haruta、Christopher T. Yokoyama、Yasuo Yamada、Masakatsu Hirose
DOI:10.1039/c39850001645
日期:——
The ethylene monothioacetals and dithioacetals of alkylcyclohexanones react with copper(II) bromide to give 2,3-dihydro-1,4-benzoxathiine and 2,3-dihydro-1,4-benzodithiine derivatives, respectively.
A Facile One-Pot Preparation of 2,3-Dihydro-1,4-benzodithiins and 2,3-Dihydro-1,4-benzoxathiins
作者:Hiroyuki Tani、Shunsuke Irie、Kazunori Masumoto、Noboru Ono
DOI:10.3987/com-93-6348
日期:——
2,3-Dihydro-1,4-benzodithiines and 2,3-dihydro-1,4-benzoxathiines were prepared in good yields by a one-pot procedure from the reaction of cyclohexanone derivatives with ethane-1,2-dithiol or 2-mercaptoethanol using N-bromosuccinimide in dichloromethane at 0-degrees-C.