Various novel pyrano [2,3-d]pyrimidines 5 and furopyrano [2,3-d]pyrimidines 7 were synthesized in 80-99% yields via a multicomponent domino Knoevenagel/hetero-Diels-Alder reaction of 1,3-dimethyl barbituric acid with an aromatic aldehyde and ethyl vinyl ether/2,3-dihydrofuran in presence of 1 mol% of indium(III) chloride. The reaction also proceeds in aqueous media without using any catalyst, b...

Synthesis and characterization of block copolymer PEG114-b-P4VP58 and PNIPAM93-b-P4VP58. Materials. Polyethylene glycol methyl ether (CH3O-PEG114-OH, Mn ~ 5000 and the polydispersity index, PDI = 1.05) was purchased from Fluka. The monomer 4-vinyl pyridine (Acros Organics, 95%) was purified by vacuum distillation. N-isopropylacrylamide (NIPAM, Acros Organics, 99%) was purified by recrystallizat...

Transition-metal hydrides generate α-alkoxy radicals by H• transfer to enol ethers. We have measured the rate constant for transfer from CpCr(CO)3H to n-butyl vinyl ether and have examined the chemistry of radicals generated by such transfers. Radicals from appropriate substrates undergo 5-exo cyclization, with higher diastereoselectivity than the analogous all-carbon radicals. From such radica...

A review on metabolism and toxicity of the fluorinated anesthetic agent, fluroxene, is presented. Fluroxene anesthesia is nontoxic to man but fatal to many experimental animals. The fluroxene molecule (2,2,2-trifluroethyl vinyl ether) is composed of two moieties; both are toxic as a result of their metabolism: the vinyl moiety destroys heme of cytochrome P-450 while being metabolized to the fin...

The reaction of epichlorohydrin with concentrated sodium hydroxide in hexane under phase transfer conditions has surprisingly led to the formation of the symmetrical di(3-epoxyglycidyl-1-propenyl) ether 1 which contains both nucleophilic and electrophilic moieties. When it was reacted with n-butyllithium, intermediate 1 once again surprisingly generated epoxyglycidyl propargyl ether, which was ...

The photorelease of a sensitizer from a fluorinated silica surface occurs by a reaction of singlet oxygen with the vinyl ether bond linker with scission of a dioxetane intermediate. Irradiation of the released sensitizer generates singlet oxygen, which accelerates the release of more sensitizer via an autocatalytic reaction. Sigmoidal behavior of sensitizer release in n-butanol and n-octanol oc...

In this study, we investigated the aggregation behaviors of amphiphilic poly(vinyl ether)s with antimicrobial activity. We synthesized a di-block poly(vinyl ether), B3826, composed of cationic primary amine and hydrophobic isobutyl (iBu) side chains, which previously showed antimicrobial activity against Escherichia coli. B3826 showed similar uptake behaviors as those for a hydrophobic fluoresc...

Two high-speed countercurrent chromatography (HSCCC) modes were compared by separation of major alkaloids from crude extract of Picrasma quassioides. The conventional HSCCC separation was performed with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water (5:5:4.5:5.5, v/v/v/v) with 200 mg loading. pH-Zone-refining CCC was performed with two-phase solvent system c...