Novel 1-phosphonyl radicals derived from 1-mono and 1,1-di-heterosubstituted 2-oxoalkylphosphonates as useful phosphoroorganic intermediates in organic synthesis
作者:Piotr Balczewski
DOI:10.1016/s0040-4020(96)01122-2
日期:1997.2
Novel 1-phosphonyl radicals 17 were obtained from 1-mono(Y=H, X=Cl, Br, SMe) and 1.1-di (Y=X=Cl) hetero substituted 2-oxoalkylphosphonates 16 under the reductive conditions () and utilized in the reactions with alkenes for the free-radical synthesis of highly functionalizedphosphonates 19 and 20. The utility of the new approach has been demonstrated by the synthesis of methylenomycin B 13, a cyclopentanoid
A new synthesis of the title compounds via acylation of α-lithio-α-phosphorylalkyl sulfides is described. Two additional approaches to these compounds, although less efficient, involve: (a) sulfenylation of O-silylated dialkyl β-ketophosphonates and (b) the Arbuzov reaction of triethyl phosphite with α-chloro-α-methylthiomethyl phenyl ketone. The keto–enol tautomerism of the title compounds and reactivity