Abstract 2-(1-Chloroethyl) and 2-(1-chloro-2-methylpropyl) furans react with sodium diethyl phosphite to give two products, 2-(1-diethoxyphosphorylmethyl) furan and 2-alkyl-5-( diethoxyphosphoryloxy) furan. The fraction of the latter product increases with increasing size of the alkyl radical. 2-Methyl substitution in the substrate completely suppresses phosphate formation. 2-(1-Chloroethyl)-5-(2-methylpropyl) furan under the action of ...