An efficient method for the synthesis of enol ethers and enecarbamates has been developed based on catalytic hydrosilane reduction of alpha-phosphonoxy enol ethers and alpha-phosphonoxy enecarbamates. This method has been applied to the total syntheses of two isoindolobenzazepine alkaloids, lennoxamine and chilenine.

Pro-Val pseudo dipeptides incorporating protio and halo enol lactones were tested for inhibitory activity against the serine proteases human leukocyte elastase (HLE), porcine pancreatic elastase, alpha-chymotrypsin, trypsin, thrombin, and urokinase. The protio enol lactones 1a-c were found to be HLE substrates but were poor alternate substrate inhibitors. The bromo enol lactone trans isomer 2a ...

Stereoselective formation of substituted 1,3-dioxolanes was achieved through an assembly of three components: alkene, carboxylic acid and silyl enol ether. The reaction proceeded via stereospecific generation of a 1,3-dioxolan-2-yl cation intermediate during oxidation of alkene substrates with hypervalent iodine. The stereoselective trapping of the cation intermediate with silyl enol ether comp...

The chlorophyll a (Chl a) special-pair model of the primary donor of photosystem I (P700) does not account in a completely adequate fashion for the magnetic resonance properties observed for P700(+). Moreover, P700 is at least 420 mV easier to oxidize than is Chl a in vitro. Neither Chl a dimer formation nor selective ligation of Chl a can account for this potential difference. Enolization of t...

palladium (ii) coordination complexes catalyze the reaction of alcohols with ketones to yield ethers. during the catalytic cycle, the alcohol adds selectively to the β-carbon (anti-markovnikov). in this work, mechanism and kinetics for the reaction of methanol with methyl vinyl ketone (mvk), being catalyzed by pd, has been theoretically investigated in detail. using quantum mechanical approach,...

A simple enol acetal underwent rapid cleavage in acidic solution to generate a difluorinated enol, which was sufficiently long-lived to be characterized by 2D NMR in a protic solvent at ambient temperature. Density functional theory calculations on a model reaction suggest that there are significant differences in protonation transition state timing between the fluorinated and nonfluorinated en...

A slight excess of silyl trifluoromethanesulfonate mediates a tandem enol silane formation-Mukaiyama aldol reaction in the presence of Hunig’s base. Preformation of the enol silane is unnecessary for efficient reactions, which proceed in 75-97% yield for the addition of aryl methyl ketones and acetate esters to non-enolizable aldehydes. Mechanistic data suggests that free amine is crucial for f...

Enol esters of 2-substituted-3-oxoalkanoates of (Z)-configuration were reduced by bakers' yeast to chiral 2-substituted-3-hydroxyalkanoates. The sy/f-selectivities of this reaction increased compared with those of the reduction of the corresponding racemic keto esters. The reaction mayproceed via an asymmetric hydrolysis of the enol esters, followed by the reduction of the resulting carbonyl gr...

The title compound, C(18)H(23)NO(5), a potential herbicide, has an enol group that is intra-molecularly hydrogen bonded to a keto O atom. The dihedral angle between the six-membered ring formed by the enol group and the aromatic benzene ring is 53.35 (6)°.