Synthesis of tert-butyl propargyl carbonate 1c
A number of studies have been performed, which are relevant to the question of whether diazepam has any action in organophosphate poisoning other than as an anticonvulsant. These studies have concentrated on various aspects of the cholinergic system, as well as the GABAergic system and cGMP concentrations. Very large doses of diazepam (20 mg/kg), increased the acetylcholine content of mouse brain (Tonkopii et al., 1978). In the corpus striatum and hippocampus of rats exposed to sarin and soman, diazepam decreased the magnitude of the elevations in choline concentrations, but not those of acetylcholine (Flynn & Wecker, 1986). On the basis of studies on the acetylcholine synthetic system of the mouse brain, Lundgren et al. (1987) suggested that in addition to observed effects on acetylcholine turnover, diazepam might have an effect on choline transport across the blood-brain barrier. Whether diazepam-induced effects on the GABAergic system are responsible for anticonvulsant activity in soman poisoning is unresolved (Lundy et al., 1978). An effect on soman-induced elevations in central nervous cGMP concentrations has been hypothesized as a mechanism of action of the benzodiazepin
of propargyl O-glycosides for the synthesis of ..
N2 - Highly Z-selective syntheses of oxazolidin-2-ones from propargylic alcohols containing internal alkynes and phenyl isocyanate were achieved by using a combination of silver acetate and N,N-dimethylaminopyridine. The catalytic system was applied to propargylic alcohols containing alkyl-substituted alkyne groups. By considering the results in the presence and absence of an electron-withdrawing group on the aromatics, it was shown that the silver catalyst effectively activates the C≡C triple bond by acting as a π-Lewis acid to produce the corresponding oxazolidinones with high Z-selectivities.
T1 - Synthesis of Oxazolidin-2-ones by Tandem Cyclization of Propargylic Alcohols and Phenyl Isocyanate Promoted by Silver Catalysts as π-Lewis Acids