In this paper, we propose an algorithm to convert a given structured LOTOS specification into an equivalent flattened model called synchronous EFSMs. The synchronous EFSMs model is an execution model for communication protocols and distributed systems where each system consists of concurrent EFSMs and a finite set of multi-rendezvous indications among their subsets. The EFSMs can be derived from a specification in a sub-class of LOTOS and its implementation becomes simpler than the straightforward implementation of the original LOTOS specification because the synchronization among the processes in the model does not have any child-parent relationships, which can make the synchronization mechanism much more complex. Some experimental results are reported to show the advantage of synchronous EFSMs in terms of execution efficiency.