Synthesis of CDE molecular fragments related to sendanin mediated by titanocene(iii)Electronic supplementary information (ESI) available: 1H and 13C spectra of all compounds are given as supplementary information. See DOI: 10.1039/c2ob25538c

A practical, brief, and diastereoselective synthesis of limonoid CDE fragments from a readily available starting material is described. The key step was the titanocene( iii )-promoted cyclization of unsaturated epoxylactones, readily prepared from α-cyclocitral. In this way, we confirm the viability of our procedure for the synthesis of a limonoid model with different functionalization patterns. We also report the antifeedant activity of epoxylactones 18 and 19 , which show significant antifeedant activity against Spodoptera littoralis and Spodoptera frugiperda , two insect species with different feeding ecologies. Fragments of limonoid were synthesized diastereoselectively using the titanocene( iii )-promoted cyclization of unsaturated epoxylactones. These compounds show significant antifeedant activity.