Steric inhibition of intramolecular cyclizations by ortho substituents. Synthesis of 1H,3H-thieno[3,4-c]thiophene, its 2,2-dioxide, and 5-ethyl-5,6-dihydro-4H-thieno[3,4-c]pyrrole
Synthesis and Reductive Desulfurization of Crown Ethers Containing Thiophene Subunit
作者:Tyo Sone、Kazuaki Sato、Yoshihiro Ohba
DOI:10.1246/bcsj.62.838
日期:1989.3
Crown ethers containing 3,4-thiophenediyl and 3,4-thiophenediylbis(methylene) subunits as a ring constituent were prepared starting from 2,5-bis(ethoxycarbonyl)-3,4-thiophenediol and 2,5-dichloro-3,4-bis(chloromethyl)thiophene, respectively. A Raney nickel desulfurization of the thiophene-containing crown ethers afforded crown ethers having two adjacent side chains, such as a methyl or ethoxycarbonylmethyl