\documentclass[border=5mm]{standalone}
\usepackage{chemfig}
\definesubmol{ro}{\textcolor{red}{O}}
\definesubmol{gme}{
\textcolor{gray}{C}|\textcolor{gray}{H}_{\textcolor{gray}{3}}
}
\definesubmol{gmer}{
\textcolor{gray}{H}_{\textcolor{gray}{3}}|{\textcolor{gray}{C}}
}
\begin{document}
\schemestart
\chemfig{(-[:-42]*5(=-=(-!{gme})-!{ro}-))(-[:78]*5(=-=-!{ro}-))(-[:198]*5(-!{ro}-(-!{gmer})=-=))}
\arrow[,,,,red]
\chemfig[angle increment=30]{(-[1]-[3]-[1]!{gme})-[9](-[7]-[5]-[7]-[5]-[7]!{gmer})-[-1]-[1]-[-1]-[1]-[-1]-[1]!{gme}}
\schemestop
\end{document}