Yields of the three easily crystallized products 5-7 were 47, 66, and 91%, respectively. The two phosphine oxides are quite hygroscopic, however, and the P-methyl compound (6) tenaciously held 1 mol of water. This behavior had been noted previously for the phenyl compo~ nd.~~~~ The phosphinic acid, on the other hand, is a nonhygroscopic, easily isolated solid. While its NMR spectrum matched that reported previously, 1 the melting ...
![8-hydroxy-8$l^C8H11O2P-phosphabicyclo[4.3.0]nona-3,10-diene 8-oxide Structure](https://image.chemsrc.com/caspic/355/70179-65-6.png)
![(+/-)-dimethyl-({(1R,6S)-6-[(dimethylamino)methyl]cyclohex-3-en-1-yl}methyl)amine Structure](https://image.chemsrc.com/caspic/241/70179-68-9.png)
