%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  2. Auflage
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%%  Beispiel 15-05-12 auf Seite 818.
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%%  Copyright (C) 2016 Herbert Voss
%% 
%%  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.
%% 
%% 
%% ==== 
% Show page(s) 1
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\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{352.81416pt}
\parindent=0pt
%StartShownPreambleCommands
\usepackage[greek=textalpha]{chemmacros}
\usepackage{chemfig}
%StopShownPreambleCommands
\begin{document}
\schemestart
  \chemfig{*6(=-(-)=O)}
  \arrow{->[\+\ch{H+}]}
  \chemleft[
    \subscheme[90]{%
        \chemfig{*6((-[2,0.33,,,draw=none]\fscrp)-=(-)-OH)}
        \arrow{<->}
        \chemfig{*6(=-(-)(-[6,0.4,,,draw=none]\fscrp)-OH)}}
  \chemright]
  \arrow(@c3--)\chemfig{*6((-[2]R)-=(-)-OH)}\arrow(@c4--)\chemfig{*6(=-(-)(-[6]R)-OH)}
\schemestop
\end{document}
