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Unexpected axial preference of the Me2N substituent on the phosphorus atom of the P(III) 1,3,2,-oxazaphosphorinane ring system

✍ Scribed by Yande Huang; Nasreen N. Mullah; Alan E. Spochik; Atta M. Arif; Wesley G. Bentrude

Publisher: Elsevier Science
Year: 1991
Tongue: French
Weight: 279 KB
Volume: 32
Category: Article
ISSN: 0040-4039
DOI: 10.1016/s0040-4039(00)92115-4

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✦ Synopsis

The conformations of a series of 5,5-dimethyl-Z-Z-1,3f2-oxazaphosphorinanes (Z = MeO, (CF,),CHO, Ph, MeaN, and I-Pr N) have been investigated by H NMR spectroscopy and by X-ray crystallography. Surprising y, T Me,N displays a strong preference for axial attachment to the ring; and 1-Pr,N also is axial to a large extent (>50%). The structural properties of the six-membered rings which result on replacement of certain of the carbon atoms of the cyclohexane ring with the heteroatoms 0, N, S, and P have been widely studied.' Such rings are structural components of the important antitumor agent cyclophosphamide (1, a 1,3,2-oxazaphosphorinane) and the bioregulator molecules CAMP (2) and cGMP (3). Recently, phosphorus-stabilized carbanlons formed from six-membered ring cyclic C 0 p"

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