Enzymes in organic synthesis. 31. Preparations of enantiomerically pure bicyclic [3.2.1] and [3.3.1] chiral lactones via stereospecific horse liver alcohol dehydrogenase catalyzed oxidations of meso diols
Synthesis of Natural-Product-Like Molecules with Over Eighty Distinct Scaffolds
作者:Daniel Morton、Stuart Leach、Christopher Cordier、Stuart Warriner、Adam Nelson
DOI:10.1002/anie.200804486
日期:2009.1
Seeking scaffold diversity: A synthetic approach for the combinatorial variation of the scaffolds of small molecules is described. Using just six basic reaction types, compounds with 84 distinctscaffolds were prepared. The compounds had many natural‐product‐like structural features including rich stereochemistry, heterocyclic and unsaturated ring systems, and dense functionalization.
Highly asymmetric enzymatic hydrolysis and transesterification of meso-biscacetoxymethyl)- and bis(hydroxymethyl)cyclopentane derivatives: an insight into the active site model of Rhizopus Delemar lipase
作者:Masakazu Tanaka、Miki Yoshioka、Kiyoshi Sakai
DOI:10.1016/s0957-4166(00)80143-3
日期:1993.5
% ee. In explanation of these high enantioselectivities of RDL, the simple box-type active site model of enzyme was tentatively proposed. On the other hand, PFL-catalysed transesterification of meso-bis-(hydroxymethyl) cyclopentane (6) afforded (+)-16 of >99 % ee. The obtained (+) and (−)-16 were converted into the natural carbocyclicnucleoside (−)-aristeromycin (25), respectively.
Total Synthesis of Gracilioether F: Development and Application of Lewis Acid Promoted Ketene-Alkene [2+2] Cycloadditions and Late-Stage CH Oxidation
作者:Christopher M. Rasik、M. Kevin Brown
DOI:10.1002/anie.201408055
日期:2014.12.22
The first synthesis of gracilioetherF, a polyketide natural product with an unusual tricyclic core and five contiguous stereocenters, is described. Key steps of the synthesis include a Lewisacidpromotedketene–alkene [2+2] cycloaddition and a late‐stage carboxylic acid directed C(sp3)Hoxidation. The synthesis requires only eight steps from norbornadiene.
Die Herstellung von 3, 5-disubstituierten Cyclopentenen durch Ozonolyse von Norbornadien
作者:C. A. Grob、H. R. Pfaendler
DOI:10.1002/hlca.19700530828
日期:——
The ozonization of norbornadiene is described. Oxidation of the intermediate with silver oxide furnishes 4-cyclopentene-cis-1, 3-dicarboxylic acid, reduction with sodium borohydride cis-1, 3-bis-hydroxymethylcyclopent-4-ene. The latter was converted to cis-3, 5-dimethylcyclopentene by reduction of the corresponding bis-tosylate with LiAlH4. Hydrogenation of the ozonization intermediate over palladium-lead
Fructose 1,6-Bisphosphate Aldolase fromStaphylococcus carnosus: Overexpression, Structure Prediction, Stereoselectivity, and Application in the Synthesis of Bicyclic Sugars