%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 8-2-47 on page 543.
%% 
%%  Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert Vo\ss 
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{207.83385pt}
\StartShownPreambleCommands
\usepackage[pictex]{m-ch-en}
\StopShownPreambleCommands
\begin{document}
\definechemical[sixring]
  {\chemical[SIX,B,R,RZ135]%
            [R_1,R_3,R_5]}
\startchemical[size=small]
  \chemical[sixring,SIX,RZ246]
           [A,B,C]
\stopchemical
\end{document}