# How to use align* environment inside multirow

I am constructing a table, and trying to use an align* environment inside multirow. Unfortunately I have had no luck in getting this to work so far.

This is a minimal working example of what I am trying to do:

\documentclass[a4paper,10pt]{article}

\usepackage{amsmath}
\usepackage{rotating}
\usepackage{multirow}
\usepackage{booktabs}

\begin{document}

\begin{sidewaystable}
\begin{center}
\begin{tabular}{l l}
\toprule
Title & Title \\
\midrule
\multirow{10}{*}{aligned equation to come here}
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
\midrule
\multirow{3}{*}{aligned equation to come here} & some text \\
& some text \\
& some text \\
\bottomrule
\end{tabular}
\end{center}
\end{sidewaystable}

\end{document}


The aligned equation I would like to insert, looks something like this:

\begin{align*}
a b \rightarrow &c d, \\
&c \rightarrow e f
\end{align*}


Unfortunately, when I try to insert this into the table, I get a lot of error messages (missing \endgroup, missing \$, missing {, ...). At this point I have no idea how to solve this, and googling the problem also didn't point me to any solution.

One other thing, I am using a sidewaystable because the actual text column is very wide, and otherwise things don't fit on a page.

Any help would be much appreciated!

You need to give a width otherwise multirow acts like a lcr column and does not allow display material:

\documentclass[a4paper,10pt]{article}

\usepackage{amsmath}
\usepackage{rotating}
\usepackage{multirow}
\usepackage{booktabs}

\begin{document}

\begin{sidewaystable}
\begin{center}
\begin{tabular}{l l}
\toprule
Title & Title \\
\midrule
\multirow{10}{2cm}{
\begin{align}
a=2\\
3=4
\end{align}}
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
& some text \\
\midrule
\multirow{3}{2cm}{
\begin{align}
a=2\\
3=4
\end{align}} & some text \\
& some text \\
& some text \\
\bottomrule
\end{tabular}
\end{center}
\end{sidewaystable}

\end{document}