The asymmetric direct aldol condensation of aldehydes with ethyl- and propylketones is catalyzed by syn-alpha-aminoalcohol-Yb(OTf)3 complexes, yielding the anti-1,3-diol monoesters with high diastereocontrol and good enantioselectivity. Three adjacent stereogenic centers are created in a simultaneous aldol condensation and Evans-Tishchenko reduction in an acyclic system.

1. Elastins purified by various methods from the ligamentum nuchae and the lungs of cattle of various ages were analysed for amino acid compositions and lysine-derived cross-links. 2. In fully mature elastins from adults the main cross-links were desmosine, isodesmosine and lysinonorleucine and the so-called aldol-condensation product. Trace amounts of merodesmosine were also found. 3. During t...

The strategy for converting glucose directly to new types of furanic compounds under mild conditions is based on retro-aldol condensation followed by aldol C2 and C4 fragments with acetylacetone.

In an "aldol addition" reaction an enol or enolate of an aldehyde or ketone reacts with a second aldehyde or ketone forming a new carbon-carbon bond which makes the aldol reaction an important reaction for organic synthesis. Originally, the aldol reaction used ethanal (see below) and therefore the product contained both an aldehyde and an alcohol functional group; thus it became known as the al...

In an "aldol addition" reaction an enol or enolate of an aldehyde or ketone reacts with a second aldehyde or ketone forming a new carbon-carbon bond. This makes the aldol reaction an important reaction for organic synthesis. Originally, the aldol reaction used ethanal (see below) and therefore the product contained both an aldehyde and an alcohol functional group; thus it became known as the al...