J. Galloy

1-Amino(imino)methyl-2-hydroxypyrrolidine-2-carboxylic acid monohydrate, C6H11N3O3.H2O. A cyclic form of the α-keto acid derived from arginine

M r--- 191.19, monoclinic, P2Jc, a = 6.597(3), b= 11.713 (3), c= 11.945 (4),/~, fl= 112.14(2) ° , V= 854.9 (4),/~ 3 , Z=4, Dx= 1.49 g cm -3, Mo Ka, 2 = 0.71069/~, /~ = 1.17 cm -~, F(000) = 408, room temperature, R = 0.041 for 973 unique reflections with I > 20(/). The title compound exists in the zwitterionic form with its five-membered ring exhibiting a half-chair conformation. The substituted guanidino moiety is planar with all three C--N bonds statistically equivalent (1.329 (7),~1. The structure contains a water of hydration which partici- pates in an extensive network of hydrogen bonds.

9-Oxothioxanthenium methylides

1 H and 13C N.m.r., i.r., and X-ray data indicate that thioxanthones react with carbenes generated from dialkyl diazomalonates to form sulphonium ylides which contain a comparatively flat heterocyclic ring.