Asymmetric [2,3]-Wittig rearrangement of the dienolates of chiral secondary alcohol-substituted β-pyrrolidinyl-γ-allyloxyl-α,β-unsaturated esters: total synthesis of (+)-eldanolide

Stereoselective synthesis of 2,3,4-highly substituted oxetanes by intramolecular C–C bond forming Michael addition

A wide variety of 2,3,3,4-tetrasubstituted oxetanes and 3-α,β-unsaturated ester substituted oxetanes were synthesized starting from vinylogous urethane derivatives.

The use of the lactone motif in chemical communication

A wide variety of organisms communicate via the chemical channel using small molecules. A structural feature quite often found is the lactone motif. In the present paper, the current knowledge on such lactones will be described, concentrating on the structure, chemistry, function, biosynthesis and synthesis of these compounds. Lactone semiochemicals from insects, vertebrates and bacteria, which this article will focus on, are particularly well investigated. In addition, some ideas on the advantageous use of lactones as volatile signals, which promoted their evolutionary development, will be discussed.

One-step preparation of O-(α-bromoacyl) cyanohydrins by minor enantiomer recycling: synthesis of 4-amino-2(5H)-furanones

O-(α-Bromoacyl) cyanohydrins were prepared in a single step from a range of different aldehydes in combination with α-bromoacyl cyanides. By the use of a cyclic procedure where the two minor diastereoisomers from a chiral Lewis acid-catalyzed reaction undergo Candida antarctica lipase B (CALB)-catalyzed hydrolysis followed by dehydrocyanation to regenerate the starting material, the products were obtained in good to high yields and in most cases with excellent diastereoselectivites. The synthetic importance of these compounds was demonstrated by the synthesis of 4-amino-2(5H)-furanones, a class of compounds that have shown both biological activity and utility as synthetic intermediates. This transformation was achieved by an intramolecular Blaise reaction, which gave the products in high to excellent yields and enantiomeric ratios.