Start sections in an odd page only in one chapter

Question

I need to make all the sections of a certain chapter of my document (a book) appear in an odd page. Any ideas?

Answer 1

Here you have two solutions. The first one defines a new command \mysection; the second one automates the procedure thanks to etoolbox, but requires a conditional at the opening and one at the end of the chapter in which the sections must appear on an odd page. Here is a mwe:

\documentclass{book}
\usepackage{lipsum}

% first solution
\makeatletter
\newcommand{\mysection}[1]{%
 \ifnum\value{section}=0\relax
  \else
   \cleardoublepage
  \fi
 \section{#1}}
\makeatother

% second solution
\usepackage{etoolbox}
\newif\ifoddsections
\pretocmd{\section}{
 \ifoddsections 
 \ifnum\value{section}=0\relax
  \else
    \cleardoublepage
   \fi
 \else
\fi}{}{}

\begin{document}
\chapter{With a new section command}
  \mysection{The first section of the chapter}\lipsum[1-6]
  \mysection{A section starting on an odd page}
  \mysection{A section starting on an odd page}
  
\chapter{With a conditional} 
\oddsectionstrue
  \section{The first section of the chapter}\lipsum[1-6]
  \section{A section starting on an odd page}
  \section{A section starting on an odd page}
\oddsectionsfalse

\chapter{A normal chapter with sections on even or odd pages}
  \section{The first section of the chapter}\lipsum[1-6]
  \section{A section starting on an odd page}
  \section{A section starting on an odd page}
\end{document}

Answer 2

I assume you want the sections to start the page, and not start halfway down an odd page? If there's not too many sections, you could just put \cleardoublepage before all of them. A higher level approach would be etoolbox's \pretocmd{\section}{\cleardoublepage}{}{}, appropriately localized. But that might also run into trouble, since \section does some weird stuff.