Reduction of ribono-1,4-lactones and gulono-1,4-lactone as well as ribono-1,5-lactone and glucono-1,5-lactones with LTBH (1.2 equiv.) in CH2Cl2 at 0 °C for 30 min provided the corresponding pentose or hexose hemiacetals in high yields. Commonly used in carbohydrate chemistry protecting groups such as trityl, benzyl, silyl, acetals and to some extent acyls are compatible with this reduction.

The psychrotolerant bacterium Pectobacterium atrosepticum produces four N-acyl homoserine lactones under a wide range of temperatures. Their thermoregulation differs from that of the exoenzyme production, described as being under quorum-sensing control. A mechanism involved in this thermoregulation consists of controlling N-acyl homoserine lactones synthase production at a transcriptional level.

A copper-catalyzed cascade reaction of α,β-unsaturated esters with keto esters is reported. It features a copper-catalyzed reductive aldolization followed by a lactonization. This method provides a facile approach to prepare γ-carboxymethyl-γ-lactones and δ-carboxymethyl-δ-lactones under mild reaction conditions.

The recent discovery and structure elucidation of approximately 100 new sesquiterpene lactones during a systematic study of Artemisia and other genera of the family of Compositae in our laboratory (16) have provided the opportunity for further investigations on the potential of these sesquiterpene lactones as new therapeutic agents. Much of the earlier study on sesquiterpene lactones for medici...

Goniothalamus spp. are widely distributed is the island of Borneo. About 40 species of Goniothalamus have been recorded in Borneo. Goniothalamus spp. are widely used in traditional medicinal practices in Borneo especially in treating diarrhea, fever, skin diseases, antidotes and most commonly used as postparturation aids and as abortifacient. Some of the species are also being used as natural i...

A Barbier reaction-Heck arylation sequence from α-bromomethylbutenolide to fused tri and tetracyclic lactones has been developed. The first step involving a Barbier reaction enabled installing ortho-bromoaromatics in α-ylidene γ-lactones. The latter substrates were subjected to intramolecular Heck reaction conditions which selectively afforded 6,5,5 or 6,6,5 fused ring systems depending on the ...

An efficient carboesterification of alkenes with anhydrides promoted by MnO2 has been developed to afford functionalized γ-lactones in good to excellent yields. This method shows a broad substrate scope and provides a valuable and convenient synthetic tool for constructing γ-lactones.