An efficient totalsynthesis of (−)-epothilone B has been achieved in ca. 8% yield over 11 steps from 9 (or 10 steps from 7/8), which features a bissiloxane-tethered ring closing metathesis reaction to approach the trisubstituted (Z) double bond and forms a new basis for further development of an industrial process for epothilone B and ixabepilone.
Total Synthesis and Selective Activity of a New Class of Conformationally Restrained Epothilones
作者:Mamoun M. Alhamadsheh、Shuchi Gupta、Richard A. Hudson、Lalith Perera、L. M. Viranga Tillekeratne
DOI:10.1002/chem.200701143
日期:2008.1.7
Stereoselective total syntheses of two novel conformationally restrained epothiloneanalogues are described. Evans asymmetric alkylation, Brown allylation, and a diastereoselective aldol reaction served as the key steps in the stereoselective synthesis of one of the two key fragments of the convergent synthetic approach. Enzyme resolution was employed to obtain the second fragment as a single enantiomer
Volatile Amphibian Pheromones: Macrolides from Mantellid Frogs from Madagascar
作者:Dennis Poth、Katharina C. Wollenberg、Miguel Vences、Stefan Schulz
DOI:10.1002/anie.201106592
日期:2012.2.27
Amphibians like water, but do they also notice volatile compounds in the air? Yes, they do. Macrolides, such as phoracantholide J (see picture; upper right structure) or the newly discovered natural product gephyromantolide A (left structure), are used for communication by mantelline frogsfromMadagascar.
New strategy for the synthesis of the taxane diterpenes: Formation of the BC-rings of taxol via a [5+2]-pyrylium ylide-alkene cyclization, ring expansion strategy
The BC-rings of taxol can be synthesized using an intramolecular [5+2]-pyrylium ylide-alkene cyclization, followed by gem-methylcyclopropanation and reductive cleavage of the internal cyclopropane bond.
Taxane diterpenes 1. Control of relative and absolute stereochemistry in intramolecular pyrylium ylide-alkene cyclizations for the synthesis of taxol precursors
作者:William E. Bauta、John Booth、Mary E. Bos、Mark DeLuca、Louis Diorazio、Timothy J. Donohoe、Christopher Frost、Nicholas Magnus、Philip Magnus、José Mendoza、Philip Pye、James G. Tarrant、Stephen Thom、Feroze Ujjainwalla
DOI:10.1016/0040-4020(96)00867-8
日期:1996.11
Intramolecular pyrylium ylide-alkene cyclizations provide control of the absolute stereochemistry at the crucial C-19 angular methyl group, and leads to bicyclo[5.4.03,8]undecenones that contain the structural elements of the B/C rings of the taxanes.