The structure of 2-phenylperhydro-1,2-oxazolo[3,2-c] [1,4]oxazine

The title compound crystallizes in the monoclinic space group P2₁/n, with a=9.590(6), b=11.574(2), c=9.609(2) Å, β=105.72(3)^o and Z=4. The structure was solved by direct methods and refined by full matrix least squares methods to R=0.039 for 1899 observed reflections. The stereochemistry of this 6/5 ring system is found to be cis-fused with C(3)-C(4) bond in the axial and N(9)-O(1) bond in equatorial disposition. The six-membered ring in the molecule is in the chair and the five-membered isoxazolidine ring adopts an envelope conformation.