XyMTeX

\documentclass{article}
\usepackage{xymtex}
\pagestyle{empty}
\begin{document}

\cyclohexanev{
    2SA==H;
    2SB==NH2;
    3Sd==OH;
    3Su==H
  }

\end{document}

\documentclass{article}
\usepackage{xymtex}
\pagestyle{empty}
\begin{document}

\furanose{
    1Sa==H;
    2Sb==H;
    2Sa==OH;
    3Sb==H;
    3Sa==OH;
    4Sa==H;
    4Sb==HOC\rlap{H$_{2}$};
    1Sb==\fiveheterov[bd]{
        1==N;2==N;4==N
     }
    {1==(yl);3==CONH$_{2}$}
 }

\end{document}

La seguente sintesi della saccarina è stata realizzata con XyMTeX v. 5.00a:

\documentclass{article}
\usepackage{xymtexpdf}
\usepackage{chmst-pdf}
\pagestyle{empty}
\begin{document}

\begin{ChemEqnarray*}
&&
\bzdrv[l]{2==;3==\squareplanar{4==(yl);0==S;%
2==NH$_{2}$;3D==O;1D==O}}\qquad \qquad
\reactrarrow{40pt}{2cm}{2 KMnO$_{4}$}{NaOH}
\bzdrv[l]{2==\dimethylenei{2==O$^{-}$Na$^{+}$}%
{1D==O;1==(yl)};3==\squareplanar{4==(yl);0==S;%
2==NH$_{2}$;3D==O;1D==O}}\qquad \qquad
\begin{tabular}[b]{l}
+ 2 KOH \\
+ 2 MnO$_{2}$\\
+ H$_{2}$O
\end{tabular}
\\ \noalign{\vskip20pt}
&&
\qquad \reactrarrow{40pt}{2cm}{HCl conc.}{}
\nonaheterov[dfh]{1==S;2==N;1==\RightAtomBond(20,30)%
{7D==O};1==\LeftAtomBond(20,30){7D==O}}{2==H;3D==O}
\end{ChemEqnarray*}

\end{document}