[Synthesis of CNS-activity of pyran derivatives: 6,8-dioxabicyclo(3,2,1)octane]

The amino nitriles 4a,b and 5a,b, prepared from (1S,5R)-6,8-dioxabicyclo[3,2,1]octan-4-one (2), react with phenylmagnesium bromide to afford the diastereomeric 4-amino-4-phenyl derivatives 7a,b and 8a,b, respectively. The diastereomeric piperidine derivatives 7b and 8b show different CNS-activity.