Elucidation of the relative and absolute stereochemistry of the kalimantacin/batumin antibiotics
作者:Iain R. G. Thistlethwaite、Freya M. Bull、Chengsen Cui、Paul D. Walker、Shu-Shan Gao、Luoyi Wang、Zhongshu Song、Joleen Masschelein、Rob Lavigne、Matthew P. Crump、Paul R. Race、Thomas J. Simpson、Christine L. Willis
DOI:10.1039/c7sc01670k
日期:——
acid was assigned by spectroscopic methods, but the relative and absolutestereochemistry of the five stereocentres remained unknown. Herein we describe isolation of kalimantacin A and two further metabolites 17,19-diol 2 and 27-descarbomyl hydroxyketone 3 from cultures of P. fluorescens. Their absolute and relative stereochemistries are rigorously determined using a multidisciplinary approach combining
A Ring Closing Metathesis Approach to the Formal Synthesis of (+)‐Callyspongiolide
作者:Kwang‐Yoon Ko、Zoe E. Wilson、Daniel P. Furkert、Margaret A. Brimble
DOI:10.1002/cctc.202001139
日期:2020.11.19
An enantioselective synthesis of macrocyclic core of (+)‐callyspongiolide is described, constituting a formalsynthesis of this natural product. The synthetic strategy constructs the 14‐membered macrocyclic domain via Yamaguchi esterification followed by a challenging ring‐closingmetathesis (RCM) to effect the final formation of the macrolactone.
Toward a Total Synthesis of Okilactomycin. 2. A Metathesis-Based Approach to the Heavily Functionalized Cyclohexane Ring
作者:Serge L. Boulet、Leo A. Paquette
DOI:10.1055/s-2002-28511
日期:——
addition of a functionalized allylic Grignardreagent in tandem with ring closing metathesis forms the basis of a direct, highly stereocontrolled route to the cyclohexenylmethanol 10. Ensuing Sharpless epoxidation very efficiently leads to construction of epoxide 11. This intermediate and its benzyl ether were found to undergo regiocontrolled oxirane ring cleavage with cyanide and chloride ions. However