Synthesis of certain spiro compounds

The synthesis of certain N-substituted azaspirodiones and azaspiranes is described. Fusing equimolecular amounts of 2-oxaspiro [4.4]nonane-1.3-dione with a number of amino compounds afforded the corresponding N-substituted azaspirodiones. However, with certain o-substituted anilines, no condensation took place. Reduction of the N-haloaryl azaspirodiones gave the corresponding oxygen free compounds. Other azaspiranes were isolated as the quaternary methiodides. Applying the Mannich conditions to 2-azaspiro[4.4]nonane-1.3-dione yielded the N-Mannich bases.