THE ANOMERIC EFFECT IN DITHIATRIAZINES

The Anomeric Effect in Dithiatriazines From (CF3CN3S2)n (1) and XeF2, Br2, or (CF3)2NO* the corresponding S,S‐substituted dithiatriazines CF3CN3S2F2 (2), CF3CN3S2Br2 (3), and CF3CN3S2[ON(CF3)2]2 (4) are prepared. An electron diffraction study of 2 in the gas phase results in a slightly aplanar 6‐membered ring with chair conformation and both S‐F bonds in axial position. MNDO calculations show that the position of the substituents at the sulfur atoms is strongly dependent on these substituents and on the ring geometry. The cis preference is the result of an anomeric effect. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim