Synthesis of cycloheptanes using radical cyclisations of methylenecycloproprane derivatives

Underwood, Jonathan James (2003) Synthesis of cycloheptanes using radical cyclisations of methylenecycloproprane derivatives. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

This thesis is concerned with the synthesis and radical cyclisations of compounds containing a methylenecyclopropane moiety. The focus of the work is to use a samarium (II) iodide-mediated radical cyclisation to prepare cycloheptanes.

Chapter two describes the synthesis of basic precursors (308 and 309) to explore the potential for the desired transformation and also the optimum conditions required. Chapter three reports the synthesis an cyclisation of precursors with an aromatic backbone (374) or a cyclohexyl backbone (354) and either an alcohol or allyl ether moiety; trans decalins were produced in moderate yields. Chapter four details the synthesis and cyclisation of open-chain precursors that have either an alcohol (491), allyl ether (492) or propargyl ether (493) functionality present; many different bicyclic products were isolated. Chapter five outlines the synthesis and cyclisation of a series of cyclopentanone (572, 573 and 574) precursors leading to bicyclic and tricyclic products. (Fig. 3740)