\documentclass[12pt,border=1pt,crop,multi=false,tikz,class=scrartcl]{standalone} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{chemfig,chemmacros} \usepackage{lmodern} \usetikzlibrary{decorations.pathmorphing}  \chemsetup[chemformula]{font-shape=sf,format=\sffamily} \renewcommand*{\familydefault}{\sfdefault} \renewcommand*\printatom[1]{\ensuremath{\mathsf{#1}}} \setatomsep{2.5em} \setdoublesep{.6ex} \setarrowdefault{,1,thick} \setbondstyle{thick} %\setarrowlabelsep{1em}  \makeatletter \begin{document} \definesubmol\nobond{-[,0.25,,,draw=none]}  %\schemedebug{true} \schemestart[][north] 	\chemfig{RO-[:30](=[2,.75]O)-[:-30]-[:30]Me}     \arrow{->[\ch{LiNR2}]}     \subscheme{     	\chemleft[\chemfig{Li?-[:10]N(-[:-120]R)(-[2]R)-[:-10]H-[:60](-[2]H)(-[:-20]Me)-[:190](-[:60]OR)=[:-190]O?}\chemright]         \arrow{0}[-90,.1]         \chemleft[\chemname{\chemfig{Li?-[:10]N(-[:-120]R)(-[2]@{a1}R)-[:-10]H-[:60](-[2]@{a2}Me)(-[:-20]H)-[:190](-[:60]OR)=[:-190]O?}}{\footnotesize unfavourable syn-pentane}\chemright]         \chemmove{\draw[-, shorten >=2pt, shorten <=2pt] (a1) .. controls +(90:1c	m) and +(130:5mm) .. (a2);}     }     \arrow     \subscheme{     	\subscheme{\chemname*{\chemfig{RO-[:30](-[2]OLi)=[:-30]-[6]Me}}{favored}\qquad {E--enolate}}         \arrow(c6--){0}[-90,.5]         \subscheme{\chemname*{\chemfig{RO-[:30](-[2]OLi)=[:-30]-[:30]}}{unfavored} \,{Z--enolate}}     } \schemestop \end{document}