Ring expansion reactions of 4-amino-1,1-dioxo-[1,2,3,5]-thiatriazoles

An unusual ring-expansion reaction of 4-amino-1,1-dioxo-[1,2,3,5]-thiatriazoles has been identified that produces the relatively rare 5-amino-1,1-dioxo-[1,2,4,6]-thiatriazines and. Initial alkylation of the thiatriazole with alpha-halo-esters at N-3 produces alpha-substituted esters which, under basic reaction conditions, undergo opening of the thiatriazole ring and re-closure to a thiatriazine ring. Similar alkylations of with diethyl chloromalonate and ethyl dichloroacetate lead to the loss of SO2 and the production of triazine and triazole, apparently by an initial alkylation at N-5. The reaction of with phenacyl bromides or a phenacyl dibromide forms fully unsaturated 5-amino-1,1-dioxo-[1,2,4,6]-thiatriazines.     

Lateral control of skeletal rearrangement by complexation of thebaine with Fe(CO)3

Temporary attachment of Fe(CO)₃ to thebaine allows access to northebaine, 14α-substituted thebainone derivatives, and a rearranged codeinone analogue lacking the oxide ring and in which the dihydrophenanthrene nucleus is replaced by a dihydrofluorene one.     

Algebraic operator method for the construction of solitary solutions to nonlinear differential equations

Solutions of the KdV equation are derived by the algebraic operator method based on generalized operators of differentiation. The algebraic operator method based on the generalized operator of differentiation is exploited for the derivation of analytic solutions to the KdV equation. The structure of solitary solutions and explicit conditions of existence of these solutions in the subspace of initial conditions are derived. It is shown that special solitary solutions exist only on a line in the parameter plane of initial and boundary conditions. This new theoretical result may lead to important findings in a variety of practical applications.