documentclass[doc, a4paper]{apa6}
usepackage{chemfig}

definesubmol{x}{(-[4]H)(-[0]OH)}
definesubmol{y}{(-[0]H)(-[4]HO)}

begin{center}
schemestart[]
    chemname{chemfig{[2]CH_2 cdot OH-!x-!x-!y-(-[0]OH)=(-[3]H)-[1]OH}}{1, 2 Enediol}
    arrow
    +
    arrow(--tri){0}[90,0.15]
    chemname{chemfig{[2]CH_2 cdot OH-(-[0]OH)=(-[3]H)-[1]OH}}{Triose Enediol}
    arrow(--gli){0}[-90,0.30]
    chemname{chemfig{[2]CH_2 cdot OH-(-[4]H)(-[0]OH)-(-[3]H)=[1]O}}{D-Gliceraldehído}
        arrow
        chemname{chemfig{[2]CH_3-(=[0]O)-(-[3]H)=[1]O}}{Metilglioxal}
        arrow
        chemname{chemfig{[2]CH_3-!x-(-[3]HO)=[1]O}}{D-Ácido Láctico}
        arrow(@tri--){<=>}
        chemname{chemfig{[2]CH_2 cdot OH-(=[0]O)-CH_3}}{Dihidroxiacetona}
schemestop
end{center}