127973-99-3Relevant academic research and scientific papers
Iterative Synthesis of Selectively Substituted α,β-Unsaturated and Saturated Medium-Ring Lactones
Fouque, Elie,Rousseau, Gerard,Seyden-Penne, Jacqueline
, p. 4807 - 4817 (2007/10/02)
Chloro, chloromethyl and chlorofluoro carbenoids, generated by reaction of a base on the corresponding halides, were added to trimethylsilyl enol ethers derived from lactones, to give 1--2-chlorobicyclooxanes.Thermal rearrangement of these adducts led to the α,β-ethylenic lactones, corresponding to a one-carbon ring expansion of the starting lactones.After hydrogenation, with the same iterative sequence a new one-carbon ring expansion could be performed.This method allowed the preparation in good yields of hitherto unknown medium-ring lactones.Spectroscopic and physicochemical properties of the isomeric unsaturated lactones were examined.For the 9- and 10-membered series, the trans isomers could be readily isomerized by I2 into the cis isomers or gave diolides under acidic conditions.
