Efficient Approach to 4-Oxo-2-alkenylphosphonates via Regiospecific Friedel−Crafts Acylation
摘要:
Treatment of allylic and vinylic phosphonates with excess LiHMDS, followed by addition of chlorotrimethylsilane, afforded alpha- and gamma- silylated allylic phosphonate mixtures. Without separation, these mixtures underwent the Friedel-Crafts reaction and base-promoted isomerization to give 4-oxo-2-alkenylphosphonates, which can serve as building blocks for the construction of polyethylenic chains.
Synthesis of Phostones via the Palladium-Catalyzed Ring Opening of Epoxy Vinyl Phosphonates
作者:Giri Raj Gnawali、Nigam P. Rath、Christopher D. Spilling
DOI:10.1021/acs.joc.9b00905
日期:2019.7.5
The reaction of epoxy aldehydes with tetraethyl methylenediphosphonate gave γ,δ-epoxy vinyl phosphonates. The palladium-catalyzed addition of primary alcohols gave the monoprotected diols as single diastereoisomers. The trans- and cis-epoxides lead to opposite (syn and anti) diastereoisomers of the addition products. The alkene of the vinyl phosphonates was subjected to hydrogenation, and the resulting