Synfacts 2009(10): 1077-1077  
DOI: 10.1055/s-0029-1217909
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of theThieno[3,2-b]thiophene and Thieno[3,2-b]furan Bare Ring Systems

Contributor(s): Victor Snieckus, Emilie David
J. T. Henssler, A. J. Matzger*
University of Michigan, Ann Arbor, USA
Further Information

Publication History

Publication Date:
22 September 2009 (online)

Significance

Reported here is an optimized synthesis of thieno[3,2-b]thiophene as well as the first synthetic route to thieno[3,2-b]furan. The Li-Br exchange of 3-bromothiophene with t-BuLi followed by quenching with 1,2-bis(2,2-diethoxy­ethyl)disulfide afforded 1 in 94% yield. Then, treatment of 1 with a sulfonic acid resin gave the thieno[3,2-b]thiophene 2 in 71% yield. After optimization of the conditions utilizing the same method in THF thieno[3,2-b]furan 4 was synthesized from 3 in 32% yield.