This thesis describes the synthesis of putative intermediates to investigate the biosynthesis of the polyketide bacillaene and the development of a novel cyclisation reaction and its application towards the total synthesis of calyxin I. Chapter one describes the design and synthesis of a variety of analogues required for the investigation of the biosynthesis of bacillaene, a natural product isolated from extracts of Bacillus subtilis Chapter two describes the development of a new cyclisation reaction using y,δ-unsaturated alcohols with a pendant phenol and an electrophile. After much investigation a robust route was developed to y,δ-unsaturated alcohol 203 from 2-hydroxycinnamaldehyde via a asymmetric 1 ,4-conjugate addition followed by a Grignard reaction. Cyclisation of 203 with panisaldehyde in the presence of TMSOTf gave a tricyclic product 209 in 75% yield with two rings and three new stereocenters formed in one step. The final chapter describes the application of our new methodology towards the total synthesis of natural product calyxin I.