Enantioselective total synthesis and biological evaluation of (-)-solanacol.

An enantioselective synthesis of the phenyl ring-containing strioglactone, (-)-solanocol, is described. Application of a Dynamic Kinetic Resolution (DKR) in the stereo-defining step enabled a step-economical synthesis to be achieved, and allowed access to natural and non-natural enantiomers with equal facility. Results of seed germination assays and Differential Scanning Fluorimetry (DSF) measurements with the known strigolactone receptor protein, Decreased Apical Dominance 2 (DAD2), are reported.

Synthesis of highly enantio-enriched stereoisomers of hydroxy-GR24.

In contrast to a biomimetic electrophilic cyclisation cascade, we employ a contra-biomimetic nucleophilic cyclisation cascade to give the tricyclic core of 4-hydroxy-GR24 in a single step. Kinetic resolution using a stereoselective Noyori transfer hydrogenation enables the concise synthesis of any enantiomerically enriched 4-hydroxy-GR24 stereoisomer.

Synthesis of carbazoloquinone natural products 'on-water'.

The total synthesis of a number of carbazolo-1,4-quinone natural products using on-water chemistry is described. A recently developed domino 'in-water, on-water' process is employed to rapidly and efficiently generate königinequinone A, which subsequently enables access to murrayaquinones B, C, D and E, and pyrayaquinones B and C, via a remarkably facile on-water catalysed Claisen rearrangement.

Insights into structure-activity relationships and CNS therapeutic applications of NR2B selective antagonists.

Excessive stimulation of NMDA receptors is involved in various CNS pathologies such as Parkinson's disease, acute and chronic pain and cerebral ischaemia. The use of NMDA antagonists as therapeutic agents has been restricted as a result of unwanted side effects including hallucinations and loss of co-ordination. NR2B subtype selective antagonists have previously shown a therapeutic effect without causing the side effects of broad spectrum NMDA antagonists. Considerable research has since been devoted to the development of orally bioavailable, selective NR2B antagonists and their applications in various neurological diseases. The improved therapeutic index of these compounds is expected to be the result of the subtype selectivity and cellular location of the NR2B receptors within the CNS. This review describes recent advances in the development of NR2B antagonists as well as their therapeutic applications.

Synthesis and stereochemistry of some bicyclic gamma-lactones from parasitic wasps (Hymenoptera: Braconidae). Utility of hydrolytic kinetic resolution of epoxides and palladium(II)-catalyzed hydroxycyclization-carbonylation-lactonization of ene-diols.

A palladium(II)-catalyzed hydroxycyclization-carbonylation-lactonization sequence with appropriate pent-4-ene-1,3-diols provides efficient access to the bicyclic gamma-lactones, 5-n-butyl- and 5-n-hexyltetrahydrofuro-[3,2-b]furan-2(3H)-ones (3) and (4), respectively, in both racemic and enantiomeric forms. Some of the substrate pent-4-ene-1,3-diols of high enantiomeric excess (ee) have been derived from racemic terminal epoxides by hydrolytic kinetic resolution (HKR) using cobalt (III)-salen complexes. (9Z,12R)-(+)-Ricinoleic acid also serves as a "chiral pool" source of other pent-4-ene-1,3-diols. These syntheses and enantioselective gas chromatography confirm the structures and absolute stereochemistry of the lactones in some species of parasitic wasps (Hymenoptera: Braconidae). The highly abundant 5-n-hexyltetrahydrofuro-[3,2-b]furan-2(3H)-one (4) in Diachasmimorpha kraussii and D. longicaudata is of high ee (>99%) with (3aR,5R,6aR) stereochemistry.