An efficient one-pot synthesis of novel β-amino acid derivatives containing a thiadiazole moiety was developed using a chiral squaramide cinchona alkaloid as organocatalyst. The reactions afforded chiral β-amino acid derivatives in moderate yields and with moderate to excellent enantioselectivities. The present study demonstrated for the first time the use of a Mannich reaction catalyzed by a ch...

Chiral C(2)-symmetric 3,4-bis-silyl-substituted adipic acid derivatives have been synthesised by a Mg/trimethylsilyl chloride-mediated intramolecular reductive coupling of symmetrical disiloxanes of beta-silylacrylic acid N-oxazolidinone derivatives. Efficient and short syntheses of enantiomerically pure enantiomers of 2,6-dioxabicyclo[3.3.0]octane-3,7-dione have been achieved from the bis-sily...

The widespread occurrence of amino derivatives of the sugars in products of plant and animal origin suggests the possibility that amino derivatives of the uronic acids may likewise be of importance. The uronic acids have the characteristic structures of both aldoses and aldonic acids, and hence, like the aldoses, might be expected to yield glycosyl amines [1] and like the lactones of the aldoni...

background : thymol and carvacrol have previously demonstrated larvicidal activity against aedes aegypti (diptera: culicidae). in view of this fact, it was of our interest to obtain synthetic derivatives and evaluate their larvicidal ac­tivity on ae. aegypti larvae. methods : structural modifications were performed on thymol and carvacrol in an effort to understand the functional groups necessa...

Reductions of carboxylic acid derivatives might be expected to lead either to aldehydes or alcohols, functional groups having a lower oxidation state of the carboxyl carbon. that carboxylic acids themselves are reduced to alcohols by lithium aluminum hydride. At this point it will be useful to consider three kinds of reductions: (i) catalytic hydrogenation (ii) complex metal hydride reductions ...

In this communication, we introduce squaric acid derivatives as anhydrous proton conductors. We report the synthesis, characterization and proton conductivities of four squaric acid derivatives. The anhydrous proton conductivity of one of the derivatives was 2.3 × 10(-3) S cm(-1) at 110 °C, comparable to the conductivity of molten 1H-1,2,3-triazole or 1H-imidazole.

Dried yeast has found wide acceptance as a rich source of protein and vitamin B, and has been successfully incorporated into many foods. Up to 2.5% dried yeast is frequently used in cereals and canned vegetables for infants and children. Lesser amounts are added to breads, cereals, soups, and other enriched products for adult consumption for both flavoring and nutritional purposes. The National...