Imino Diels-Alder adducts. XII. Two pyrano[3,2-c]quinolines.
The crystal structures of pyranoquinolines 9-fluoro-5-phenyl-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinoline, C18H18FNO, and 9-methyl-5-phenyl-3,4,4a,5,6,10b-hexahydro-2H-pyrano[3,2-c]quinoline, C19H21NO, are isomorphous. In both structures, the pyran ring is exo to the six-membered N-heterocyclic ring formed in the cycloaddition step. The torsion angles across the phenyl linkage for the two structures are -91.2 (1) and -88.3 (2) degrees. The striking feature in both crystal packings is that they do not contain the expected conventional hydrogen bonds, in spite of the presence of good hydrogen-bonding functionalities. Possible C-H...pi interactions are, however, observed.
Ravikumar
K
K
Laboratory of X-ray Crystallography, Indian Institute of Chemical Technology, Hyderabad 500 007, India. ravikumar_iict@yahoo.co.in
Sridhar
B
B
Mahesh
M
M
Reddy
V V Narayana
VV
D018360:Crystallography, X-Ray; D007097:Imines / Q000737:chemistry*; D015394:Molecular Structure; D011804:Quinolines / Q000737:chemistry*
D007097:Imines; D011804:Quinolines