Synthesis of Chiral Cyclopentanones through Reactions with Vinyl Sulfoxonium Salts
Synthetic derivations are often driven by the usefulness and application of certain molecules. Cyclopentanones are a class of molecules that serve an integral function in the structure of many biologically active compounds, including prostaglandins, estrone, and Bimatoprost. To investigate synthetic routes to form cyclopentanones, we started by drawing from methods previously derived in the synthesis of gamma-lactones. Our group has previously shown that gamma-lactones, which also play important roles in important biologically active molecules, can be synthesized using vinyl sulfoxonium salts and lithium enediolates. Keeping close to the methods used to synthesize the gamma-lactones, we attempted to synthesize cyclopentanones using two different ketones and two different substituted vinyl sulfur salts. From here, the methodology shifted slightly to methods derived from Johnson and co-workers, and Huckin and Weiler, wherein the sulfoxonium salt was subjected to reaction with a β-ketoester, instead of a ketone. In this case, only one β-ketoester and one vinyl sulfoxonium salt were used, while other variables were changed to see possible effects. Most recently, we moved on to investigate a different method derived from our past work, where we subject a sulfoxonium ylide to react with an acrylate, and then intercept the enolate intermediate with a ketene in a continued attempt to form cyclopentanone. 4-Methoxy substituted vinyl sulfoxonium salts fall in the scope of investigation for their electron-donating electronic effect on possible product synthesis. Acetone, 3-methyl-2-butanone, dimethyl vinyl sulfonium salt, and phenyl vinyl sulfoxonium salt fall into the scope of investigation for their potential to affect cyclopentanone yields.
Cyclopentanone, Sulfoxonium salt, Enediolates, Ylide