39 resultados para Natural products -- Synthesis
em University of Queensland eSpace - Australia
Resumo:
This review highlights structural and biosynthetic work on a group of nitrogen-functionalised terpenes that are almost exclusively found in marine invertebrates and the animals that feed on them. The chemical functionality reviewed includes isocyanides, isothiocyanates, formamides, thiocyanates, isocyanates, and dichloroimines. The literature through mid 2003 is reviewed and there are 143 citations.
Resumo:
An Eryus sp. of marine sponge from the Great Australian Bight has yielded the first reported natural occurrence of a cyclonucleoside, N-3,5'-cycloxanthosine. The structure of N-3,5'-cycloxanthosine was confirmed by detailed spectroscopic analysis and total synthesis.
Resumo:
Studies detailing synthetic approaches to a variety of biosynthetically related vibsanin-type diterpenes (i.e. vibsanin E, 15-O-methylcyclovibsanin B, 3-hydroxy-vibsanin E, furano-vibsanin A, and 3-O-methylfuranovibsanin A) are discussed. Biogenetically modelled approaches are coupled with an in-vestigation of classical and modern six- to seven-membered ring-expansion protocols, which gain access to the central core of these natural products. (c) Wiley-VCH Verlag GmbH & Co.
Resumo:
Cyclic tetrapeptides are an intriguing class of natural products. To synthesize highly strained cyclic tetrapeptides; we developed a macrocyclization strategy that involves the inclusion of 2-hydroxy-6-nitrobenzyl (HnB) group at the N-terminus and in the middle of the sequence. The N-terminal auxiliary performs a ring closure/ring contraction role, and the backbone auxiliary promotes cis amide bonds to facilitate the otherwise difficult ring contraction. Following this route, the all-L cyclic tetrapeptide cyclo-[Tyr-Arg-Phe-Ala] was successfully prepared.
