%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 8-2-5 on page 523.
%% 
%%  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}
\AtBeginDocument{\setlength\unitlength{0.09pt}}
%% Small unitlength may result in diagonal connections to vanish unless
%% a package like epic, eepic, or pict2e is being used that supports small lines
%%
\usepackage{pict2e}

\StartShownPreambleCommands
\usepackage{hetarom,epic}
\StopShownPreambleCommands
\begin{document}
\sixheterov[eb]{1==N}
    {1D==O;
     4SA==MeO;4SB==OMe;
     5==Cl;
     6==Cl}
\threehetero[H]{2==C}
 {2Sa==COOH;2Sb==COOH}
\end{document}