Abstract 3-Ethoxycarbonyl-, 3-acetyl-2-methyl-5-tert-butylfurans undergo chloromethylation underthe unusually rigorous conditions (55-60° C, 3-3.5 h). The corresponding diethylamide and nitrile were prepared by standard modification of the carboxy group. In phosphorylation of the resulting chloromethylfurans under the conditions of the Michaelis-Becker reaction, in the case of the ester and diethylamide, the phosphonate yields were close to those ...