Bestmann ylide [(triphenylphosphoranylidene)ketene] acts as a chemical linchpin that links nucleophilic entities, such as alcohols or amines, with carbonyl moieties to produce unsaturated esters and amides, respectively. In this work, the formation of α,β,γ,δ-unsaturated esters (dienoates) is achieved through the coupling of Bestmann ylide, an alcohol and an α,β-unsaturated aldehyde. Primary an...

Two different transformations of α-(isochromen-1-yl)ketones catalyzed by NHC Brønsted bases are reported. In the presence of a triazole carbene, α-(isochromen-1-yl)ketones isomerized into β-(2-(aroylmethylene)phenyl)-α,β-unsaturated ketones in 38-88% yields, while the same reaction catalyzed by an imidazole carbene produced 1-aroylnaphthalene derivatives in 90-99% yields. This work not only pro...

Mild, efficient and racemization-free synthesis of N-protected α, β-unsaturated γ-amino esters with unprecedented high E- stereoselectivity is described. This method is found to be compatible with Boc-, Fmoc- and other side chain protecting groups. The crystal conformations of the vinylogous γ-amino esters in monomers and in homo- and mixed dipeptides are studied. Further, the vinylogous homo-d...

PEGylation is a well-established technique utilized to overcome the problems related to the therapeutic applications of peptides and proteins. Reasons for the PEGylation of these biological macromolecules include reducing immunogenicity, proteolytic degradation and rapid clearance from blood circulation. Octreotide is an octapeptide analogue of naturally-occurred somatostatin. This peptide has ...

PEGylation is a well-established technique utilized to overcome the problems related to the therapeutic applications of peptides and proteins. Reasons for the PEGylation of these biological macromolecules include reducing immunogenicity, proteolytic degradation and rapid clearance from blood circulation. Octreotide is an octapeptide analogue of naturally-occurred somatostatin. This peptide has ...

A general and simple procedure to access chiral β'-amino-α,β-enones, in seven steps, from an α,β unsaturated ester has been described. The use of a Horner-Wadsworth-Emmons reaction as a key step for generating the β'-amino-α,β-enones, permits access to a range of substrates under mild conditions and in moderate to high yield.

A one-pot synthesis of new variously substituted γ-chloro-γ, β-allylic carbamates have been carried out starting from β-chloro-α, β-unsaturated aldehydes. The and the corresponding intermediates, alcohols, were fully characterized by (1H 13C) NMR, IR HRMS spectroscopic techniques. crystal structures two allylic carbamates, established single-crystal X-ray diffraction.

Chronically elevated concentrations of non-esterified fatty acids (NEFAs) in type 2 diabetes may be involved in β-cell dysfunction and apoptosis. It has been shown that long-chain saturated NEFAs exhibit a strong cytotoxic effect upon insulin-producing cells, while short-chain as well as unsaturated NEFAs are well tolerated. Moreover, long-chain unsaturated NEFAs counteract the toxicity of palm...