Diazophosphonates in Cyclic Ether Synthesis. Use of the Intramolecular Wadsworth-Emmons Reaction
Treatment of the phosphonates 3, derived from the diazophosphonates 1 and 2 by rhodium carbenoid O-H insertion reactions, with sodium hydride in THF results in intramolecular Wadsworth-Emmons reaction and formation of the cyclic ethers 4. Key words: Diazophosphonate; rhodium carbenoid; Wadsworth-Emmons; cyclic ether
Moody, Christopher J.,Sie, Eric-Robert H. B.,Kulagowski, Janusz J.
The Use of Diazophosphonates in the Synthesis of Cyclic Ethers
Two routes to cyclic ethers based on diazophosphonates are described.The first involves the rhodium(II) catalysed O-H insertion of 2-propanol followed by Wadsworth-Emmons reaction to give the enol ethers 3, and deprotection and cyclisation to the cyclic enol ethers 5.The second route involves the preparation of aldehyde and ketone phosphonates 9, also by rhodium carbenoid O-H insertion reactions, followed by functional group interconversion.On treatment with sodium hydride the phosphonates 9 undergo intramolecular Wadsworth-Emmons reaction to give cyclic ethers 13. Key Words: diazophosphonate; rhodium carbenoid; Wadsworth-Emmons; cyclic ether
Moody, Christopher J.,Sie, Eric-Robert H. B.,Kulagowski, Janusz J.