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The acid dissociation constants (KaK), the keto-enol equilibrium constants (KE), and the rate constants for enolization of the cyclic benzyl ketones 2-indanone (1a), 2-tetralone (3,4-dihydro-2(1H)-naphthalenone, 1b) and 2-benzosuberone (3,4-benzo-3-cyclohepten-1-one, 1c) were measured in aqueous solution at 25 °C. The rate constants for ketonization of the enols and the acid dissociation constants (KaE) for the corresponding enols were also determined. The presence of a conjugating phenyl group provides sufficient stabilization of the negative charge to enable these ketones to ionize in the pH range. pKaK values were determined from the rate constants for ionization of the ketones and for ketonization of the enolate ions. These values were confirmed by spectral titration. The acidity of the ketones decreases with increasing size; pKaK values are 12.2 (1a), 12.9 (1b), and 14.9 (1c). Similarly, the acid dissociation constants of the enols decrease with increasing ring size; pKaE's are 8.3 (2a), 9.2 (2b), and 10.0 (2c). Equilibrium constants for enolization also vary with ring size; pKE values are 3.8 (1a), 3.6 (1b), and 4.9 (1c).

The efficient and highly selective formation of a wide range of (hetero)cyclic cis-diol scaffolds using aminotriphenolate-based metal catalysts is reported. The key intermediates are cyclic carbonates, which are obtained in high yield and with high levels of diastereo- and chemoselectivity from the parent oxirane precursors and carbon dioxide. Deprotection of the carbonate structures affords synthetically useful cis-diol scaffolds with different ring sizes that incorporate various functional groups. This atom-efficient method allows the simple construction of diol synthons using inexpensive and accessible precursors and green metal catalysts and showcases the use of CO2 as a temporary protecting group. Protective Carbon: Aminotriphenolate complexes of FeIII and AlIII are highly efficient and selective catalysts for the conversion of functional (multi)cyclic oxiranes into the corresponding cis carbonates. Basic hydrolysis of the latter provides a series of useful cyclic cis-diol scaffolds in high yield. In this process, CO2 acts as both a temporary protecting group and an oxygen donor.

Compounds are provided of the following structure are HMG CoA reductase inhibitors and thus are active in inhibiting cholesterol biosynthesis, modulating blood serum lipids, for example, lowering LDL cholesterol and/or increasing HDL cholesterol, and trea

The synthesis of sterically hindered chiral (salen)manganese complexes bearing perfluoroalkyl ponytails and their use in asymmetric epoxidation reactions are described. For better understanding of the relative influences of steric and electronic effects o

Sterically hindered chiral (salen)manganese complexes bearing long perfluoroalkyl substituents are synthesized and successfully employed as catalysts in the enantioselective (ee = 50-87%) epoxidation of alkenes under fluorous biphasic conditions.

Hydrogenation of 2-hydroxymethylenebenzosuber-1-one (3), prepared by formylation of benzosuber-1-one (1), gives 2-hydroxymethylbenzosuberan (6) whereas KBH4 reduction of 3 affords 1,2-cis-1-hydroxy-2-hydroxymethylbenzosuberan (4). 1,2-cis-1,2-Dihydroxyben

Nucleophilic ring-opening of epoxides 2(a-d) with carbanions of different steric requirements under refluxing benzene afforded a single stereoisomer of the cyclopropane derivatives 4.The same reaction under refluxing ethanol gave the normal products, i.e. the trans-lactones 6.Mechanism and high stereoselectivity observed in the novel cyclopropane formation, and regiospecific cleavage of the cyclopropane carboxylic acids (in 4) have also been discussed in detail.