A poly(ethylene glycol)-b-poly[2-(N,N-dimethylamino)ethyl methacrylate] block copolymer possessing a reactive acetal group at the end of the poly(ethylene glycol) (PEG) chain, that is, acetal-PEG-b-PAMA, was synthesized by a proprietary polymerization technique. Gold nanoparticles (GNPs) were prepared using the thus-synthesized acetal-PEG-b-PAMA block copolymer. The PEG-b-PAMA not only acted as...

Poly(ester-acetals) have been prepared from isopropylideneglyceryI azelaaldehydate dimethyl acetal and from methyl azelaaldehydate glycerol acetal. Acid hydrolysis of isopropylideneglyceryl azelaaldehydate led to oligomeric poly (ester-acetals) with six to seven repeating units and carboxylic acid endgroups from which the sodium salt and the methyl ester could be prepared. The polymer sodium sa...

Experiences from 20 years of teaching organic chemistry at the Medical School University Geneva are recollected. Emphasis is on question how to address a large audience without particular passion for chemistry. The key lesson learned offer substantial justification every topic right beginning, before basics covered. For instance, course opens with vancomycin resistance, achieved by changing one...

STATEMENT OF PROBLEM The use of metal clasps on anterior teeth may cause esthetic problems. Recently, acetal resins have been used as an alternative tooth-colored denture clasp material to improve esthetics. However, there are few studies to support acetal resin use. PURPOSE The purpose of this in vitro study was to compare the retentive force and deformation of acetal resin and cobalt-chromi...

The reaction of trifluoroacetaldehyde N,O-acetal derivatives with 2 molar equivalents of alkyllithium reagents proceeded viabeta-elimination of fluoride followed by alkyl transfer from excess alkyllithium to the generated ketene N,O-acetal intermediate at the beta-carbon of fluorine groups.

Feulgen and Rossenbeck (1) demonstrated in 1924 in the cytoplasm of cells the presence of substances which give histochemically a color reaction with Schiff’s aldehyde reagent. Feulgen and Voit (2) at the same time showed that the aldehyde group of these substances is not free, but bound in a labile form. The authors called this substance plasmalogen. Feulgen and Bersin (3) succeeded in 1939 in...

The synthesis of the uncommon dihydropyrazinone ring was accomplished by a two-step one pot process taking advantage of the ring rearrangement of N-acylated morpholine acetal derived from serine under acidic treatment in the presence of 2,6-lutidine. The mechanism involves an N-acyl iminium intermediate resulting from morpholine acetal ring opening, which occurs after a nucleophilic attack of t...

Erythromycin A 11,12-methylene acetal (5) and the corresponding 9-methoxime, 9-dihydro, and 8-hydroxy derivatives have been prepared and their antibacterial activities compared with those of erythromycin A and its 11,12-cyclic carbonate. The simple methylene acetal 5 showed excellent activity against Gram-positive organisms in vitro.

The facile deprotection of methylene acetal protection of diols under mild conditions is established. The combination of trimethylsilyl triflate (TMSOTf) and 2,2'-bipyridyl followed by a weakly acidic hydrolysis was effective and the substrates having acid sensitive functional groups can be tolerated under the stated conditions. The selective deprotection between methylene acetal and benzopheno...