Synthetic Studieson Poecillastrin C: Synthesis ofthe C14–C35 Segment of the Macrolide Ring Model

A synthesis of the C14–C35 segment of the macrolide ring model of poecillastrin C has been achieved. The C14–C23 segment was synthesized by the stereoselective Mukaiyama aldol reaction between ketene silyl <i>N</i>,<i>O</i>-acetal possessing chiral oxazolidinone auxiliary and <i>O</i>-acetyl lactol prepared by the stereoselective conjugate addition followed by iodolactonization. The C24–C35 segment was constructed by three stereoselective vinylogous Mukaiyama aldol reactions. Both segments were coupled by the aldol reaction followed by diisobutylaluminium hydride (DIBALH) reduction to produce the C14–C35 moiety of the macrocyclic model.