Abstract
Fused ring carbocycles containing an eight-membered ring are found in many biologically active natural products and are typically used as target molecules in natural product synthesis. Although generating these types of compounds is difficult due to the enthalpic and entropic barriers associated with large rings, there is an ongoing effort in developing new methodologies that are both novel and efficient. This work utilized samarium(II) iodide (SmI2) as a single electron reductant to promote the synthesis of an eight-membered ring through a monoradical cyclization and fragmentation sequence. Initial studies concluded that the α-keto ester was unsuitable under unstabilized Wittig reaction conditions. Because the alkene functionality was required for cyclization, a new compound was synthesized using a stabilized Wittig reagent to generate a cyclopropane with either an E or Z alkene appendage. Upon cyclization studies using SmI2, it was found that neither a 6-exo-trig cyclization to v i generate a six membered ring nor a 7-endo-trig cyclization to generate an eight membered ring took place but that SmI2 preferentially reduced the electron-deficient conjugated alkene to generate a diethyl succinate.