Studies towards the synthesis of the northern polyene of viridenomycin and synthesis of Z-double bond analogues

Abstract

Viridenomycin is a structurally challenging, potentially biologically valuable molecule which has yet to succumb to total synthesis. Its instability, perhaps particularly associated with the northern polyene may contribute to the difficulties of piecing this molecule together. The synthesis of northern polyene models, including potentially stabilised analogues incorporating benzene rings as Z-alkene replacements, have been prepared using an efficient series of cross-coupling reactions. The resulting polyenes and polyene surrogates have been converted into tetraene ester and amide models of the viridenomycin system. These analogues have sufficient stability compared with the unsubstituted northern polyene analogue to be viable for future developing a strategy for the construction of viridenomycin and analogues.