Frama-C is a software analysis framework that provides a common infrastructure and a common behavioral specification language to plugins that implement various static and dynamic analyses of C programs. Most plugins do not support concurrency. We have proposed conc2seq, a Frama-C plugin based on program transformation, capable to leverage the existing huge code base of plugins and to handle concurrent C programs. In this paper we formalize and sketch the proof of correctness of the program transformation principle behind conc2seq, and present an effort towards the full mechanization of both the for- malization and proofs with the proof assistant Coq.