Hantzsch (Ann., 1896, 2 9 2, pp. 34 0 et seq.) hyponitrous acid and nitramide are to be regarded as stereoisomers, being the anti-and synforms of the same compound.
Conhydrine, CsH 17 NO, and pseudoconhydrine are probably stereoisomers, the latter being converted into the former when boiled with ligroin.
The same system can be applied to all other individual stereoisomers of tocopherols.