How to align text, structures, and arrows in chemfig package

Question

Any idea how to align the names of structures to the same height. The arrow and the plus signs, and the chemical structures, too.

I tried to align them with \chemnameinit, but does not work.

\begin{figure}
\centering
\scalebox{.6}{
\chemnameinit{\chemfig{[:210]O*3(-(-R|^1)-(-R|^2)-)}}
\schemestart
\chemname{\chemfig{R|^1-=-R|^2}}{Alqueno}
\+
\chemname{\chemfig{H_2O_2}}{Peróxido\\de hidrógeno}
\arrow{->[Base][Disolvente]}[0,2]
\chemname{\chemfig{[:210]O*3(-(-R|^1)-(-R|^2)-)}}{Epóxido}
\+
\chemname{\chemfig{H_2O}}{Agua}
\schemestop
\chemnameinit{}
}
\caption{Reacción de epoxidación. Oxidación de un alqueno en presencia de un peróxido de hidrógeno y una base orgánica.}
\label{fig:2}
\end{figure}

Answer 1

Not sure if this is the best way to go about doing it, but you can specify the anchor points used for the middle arrow, then manually shift the epxido molecule upwards with a yshift. I've marked out the changes in the following code:

\documentclass{article}
\usepackage{chemfig}

\begin{document}    

\begin{figure}
    \centering
    \scalebox{.6}{
    \chemnameinit{\chemfig{[:210]O*3(-(-R|^1)-(-R|^2)-)}}
    %\schemedebug{true} % Activate to see anchor points
    \schemestart
    \chemname{%
        \chemfig{R^1-=-R^2}
        }{Alqueno}
    \+
    \chemname{%
        \chemfig{H_2O_2}
        }{Peróxido\\de hidrógeno}
    \arrow(.mid east--.mid west) % <--------
        {->[Base][Disolvente]}[0,2] 
    \chemname{%
        \chemfig[yshift=2em]{[:210]O*3(-(-R|^1)-(-R|^2)-)} % <--------
        }{Epóxido}
    \+
    \chemname{%
        \chemfig{H_2O}
        }{Agua}
    \schemestop
    \chemnameinit{}
    }
    \caption{Reacción de epoxidación. Oxidación de un alqueno en presencia de un peróxido de hidrógeno y una base orgánica.}
    \label{fig:2}
\end{figure}

\end{document}

Addendum

You can have a look at the anchor points and how chemfig groups the molecules together using \schemedebug{true} placed before \schemestart (Uncomment it in the above code to see what I mean). It's useful when trying to align the arrows, +, and molecules in a reaction scheme.