Promoted by <i>t</i>-BuOK Reactions of 2,3-Dibromo 2-Methylpropanamides
The synthesized 2,3-dibromo-2-methyl-propanamides, differing in the nucleophilicity of the amine component, were studied in reactions with t -BuOK in THF. It was shown that in the case of anisidine amides 2,3-dibromo- N -(4-methoxyphenyl)-2-methylpropanamide and 2,3-dibromo- N -(2,5-dibromo-4-methoxyphenyl)-2-methylpropanamide, the use of 1-2 equivalents of t -BuOK allows one to obtain the corresponding azetidinones and α-methylene-β-lactams with acceptable selectivity and yields. An increase of the amount of t -BuOK (3-5 equiv) leads to a strong decrease in the yield of the final vinyl bromides and α-methylene-β-lactams. In contrast, from this series, 2,3-dibromo- N -( tert -butyl)-2-methylpropanamide reacts with t -BuOK, giving 3- ( tert -butoxymethyl)-1- tert -butylazetidine-2-one.