Functionalized methyl cis-4-oxoalk-2-enoates 2 are synthesized in a one-pot procedure by singlet oxygen oxygenation of the corresponding 2-methoxyfurans 1 in methanol and reduction of the resulting hydroperoxides 4 and 5 by the sulfides 6 which are selectively oxidized into the sulfoxides 7. The synthetic method has a wide range of applicability and affords compounds 2 stereoselectively and in good yields; concomitantly the sulfoxides 7 are obtained in excellent yields.
The 5-hydroperoxyfuran-2(5H)-ones 3 are synthesized by acid hydrolysis of the dihydrofurans 1 which are prepared in one-pot procedure by reaction of the corresponding furans 4 with singlet oxygen and methanol. The synthetic method has a wide range of applicability; however, compounds 3 unsubstituted at C-4 cannot be prepared since the corresponding dihydrofurans 1 are not formed.
Photosensitized Oxidation of Furans. 20.<sup>1</sup> A Novel Thermal Rearrangement of Suitably Substituted Alkoxyfuran Endoperoxides via Neighboring-Group Mechanism: Synthesis and Reactivity of the First Functionalized 2-Oxetanyl Hydroperoxides
作者:M. R. Iesce、F. Cermola、F. De Lorenzo、I. Orabona、M. L. Graziano