Overview of synthesis and structure of calix[n]quinone (n = 4, 6, 8)

Calix[n]quinones, a class of cyclic oligomers composed of p-benzoquinone structures connected by methylene, have multi-conjugated carbonyl structures and adjustable cavities, which make their synthesis extremely attractive. In this minireview, thesynthetic methods of calix[n]quinones and the recent synthetic experience of our group are summarized. The merits and demerits of various synthetic methods are briefly reviewed as well. When synthesizing calix[n]quinone (n ≥ 6) with a larger ring, the reduction-oxidation method is considered to be the most recommended.

Keywords: Calix[n]quinone; adjustable cavities; conjugated carbonyl; reduction-oxidation; synthesis.