LaTeX Forum

\documentclass{article}
\usepackage{chemfig}

\begin{document}

\chemfig{
  C?(-[:225]H_3C)
   (-[:135]H_3C)
   -[:-45]
  C|H_2-[:45,,1]
  CH(-[8]N=[8]C=[8]O)
   -[:90]
  CH_2
   -[:135]
  C(-[3]H_3C)
   (-[1]N=[8]C=[8]O)
   -[:225]
  H_2C?
}

\vspace*{1cm}

\chemfig{
  H_3C-[1]
  C*6([:30](-[4]H_3C)
    -CH_2
    -[,,1]CH(-[,,1]N=[0]C=[0]O)
    -[,,,1]CH_2
    -C(-[1]N=[0]C=[0]O)(-[3]H_3C)
    -H_2|C
    -[,,2]
  )}


\end{document}

\documentclass{standalone}

\usepackage[ngerman]{babel}    
\usepackage[T1]{fontenc}  
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usepackage{chemfig}
\usepackage{pgfplots}
\usepackage[locale=DE]{siunitx}
\usepackage{pgfplotstable}

\begin{document}

\begin{tikzpicture}[scale=0.6]
	\chemfig{C(-[:225]CH_3)
	(-[:135]CH_3)
	-[:-45]CH_2-[:45]CH(-[8]N=[8]C=[8]O)-[:90]CH_2-[:135]C(-[3]CH_3)(-[1]N=[8]C=[8]O)-[:225]CH_2-[:-90]}
\end{tikzpicture}

\end{document}