| abstract |
Azaspiro compounds of the formula ##STR1## wherein R 1 and R 2 independently represent hydrogen, a hydrocarbon residue which may have a substituent, or an acyl group which may have a substituent; R 3 represents hydrogen or a hydrocarbon residue which may have a substituent; each of X 1 and X 2 is oxygen or sulfur; Y represents oxygen, sulfur or a group of the formula: --N(R 4 )--, wherein R 4 represents hydrogen or a lower alkyl group; m represents 0 or 1; n represents 0 or 1, and its salt are novel compounds, possess excellent brain function-improving action, and are of use as drugs for the prevention and therapy of senile dementia of Alzheimer type, vascular-type dementia and dementia derived from Alzheimer's disease, Pick's disease, Huntington's disease, Creutzfeldt-Jakob's disease, Parkinson's disease and spinocerebellar degeneration. |