The synthesis of some bridgehead N,O-heterocycles of biological interest.

: The preparation of 5-aryl-6-oxa-1-azabicyclo[3,3,0]octanes, 6-aryl-5-oxa-1-azabicyclo[4,3,0]nonanes and 7-aryl-6-oxa-1-azabicyclo[5,3,0]decanes from the corresponding substituted omega-chlorobutyrophenones and aminoalcohols is described; and the ring opening reactions are studied. A preliminary biologic activity study has also been conducted, and demonstrated that the 5-(2,5-dimethyl)phenyl-6-oxa-1-azabicyclo[3,3,0]octane possesses antiinflammatory activity.