Preliminary studies aimed at developing reaction conditions for the fragment coupling between the C-26-C-42 fragment and the tris-oxazole fragment of ulapualide A are described. Our approach utilizes Schlosser-Wittig olefination conditions for the construction of a trans-double bond. In this study, seven different tri-alkyl and tri-aryl phosphines were evaluated in an attempt to determine the extent of trans / cis selectivity for the prospective construction of the trans-C-25-C-26 double bond of ulapualide A. (C) 1997 Elsevier Science Ltd.