\documentclass{ppex}
\nonstopmode
\AtBeginDocument {\setlength \unitlength {0.09pt}}
\usepackage {ccycle}
\pagestyle{empty}
\setlength\textwidth{207.0pt}
\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage {ccycle}
\chair{1D==O;%
  2Se==H$_3$C;2Sa==CH$_3$;%
  6Se==CH$_3$;6Sa==CH$_3$}
\end{document}