\documentclass{ppex}
\nonstopmode
\AtBeginDocument {\setlength \unitlength {0.09pt}}
\usepackage {lowcycle}
\pagestyle{empty}
\setlength\textwidth{207.0pt}
\begin{document}
\ResetPreambleCommands
\ReadyForTheFray
\usepackage {lowcycle}
\cyclobutane
  {3Sa==OH;3Sb==CH$_3$}
\cyclopropane{2Sa==COOH;%
   2Sb==COOH}
\end{document}