Synfacts 2011(2): 0150-0150  
DOI: 10.1055/s-0030-1259260
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart ˙ New York

Pillar[5]arenes

Contributor(s): Timothy M. Swager, Olesya Haze
Y. Kou, H. Tao, D. Cao*, Z. Fu, D. Schollmeyer, H. Meier*
South China University of Technology, Guangzhou, P. R. of China; Johannes Gutenberg-Universität Mainz, Germany
Further Information

Publication History

Publication Date:
19 January 2011 (online)

Significance

The unsymmetric hydroquinone 1 reacts in a p-toluenesulfonic acid catalyzed ­cyclocondensation to produce a mixture of regio­isomeric pillar[5]arenes in high yield (A-D). The ­regioisomer distribution closely follows the statistically predicted ratio (4.1:4.4:5:1 vs. 5:5:5:1). The result is consistent with the assumption that there is no electronic or steric preference for the formation of any of the three possible bridges.