2-(1-Chloroalkyl)furans in the reaction with sodium diethyl phosphite

Abstract

Reduction of 3-acylfurans with lithium alumohydride in ether yields stable secondary alcohols. By treatment with thionyl chloride in the presence of pyridine, they are converted to the corresponding chlorides. 3-(1-Chloroethyl)furan and 5-methyl-3-(1-chloroethyl)furan react with sodium diethyl phosphite to give two products: 3-(1-diethoxyphosphorylethyl)furans and 3-ethyl-2-(diethoxyphosphoryloxy)furans. The methyl group in position 5 of the furan ring increases the relative phosphate content of the mixture by a factor of approximately 2.5. Blocking of position 2 or both positions 2 and 5 of the ring with methyl groups leads to phosphoate formation only. The reaction of 2,5-dimethyl-3-(1-chloro-2-methylpropyl)furan also occurs according to the Michaelis-Becker scheme. The products of the side chain dehydrohalogenation with sodium diethyl phosphite were not found.