No abstract

The crispatenes and SNF4435 C&D are complex polypropionate derived natural products. The core structures of these compounds along with a complex unnatural structure can be easily prepared from a common polyene precursor simply by variation of the reaction conditions. The reaction pathways provide insight into the biosynthesis of these complex natural products.

The synthesis of several polycyclic compounds 1a-c, 2, and 3 has been performed through a tandem Stille/[4 + 2] cascade reaction from cyclic bis(enoltrifluomethanesulfonate) 4a-c, 5, and 6, respectively. The reaction proceeds very efficiently in a one-pot operation at roomtemperature in DMF in the presence of a catalytic amount of Pd(CH(3)CN)(2)Cl(2) and LiCl.[reaction: see text]