Synthesis of the Oxygenated Bicyclo[9.3.1]pentadecane Ring System of Phomactin A using Chromium (II)-mediated Macrocyclisation and Ring Closure Metathesis
作者:Kevin M. Foote、Matthew John、Gerald Pattenden
DOI:10.1055/s-2001-11403
日期:——
Treatment of the aldehyde vinyl iodides 17, 19 a and 19 b in DMSO with CrCl2-NiCl2 resulted in their macrocyclisation to the oxygenated ring systems 18, 20, and 21 respectively (43-63%) of the PAF antagonist phomactin A isolated from the marine fungus Phoma sp. The same bicyclo[9.3.1]pentadecane ring system 24 could also be produced by treatment of the polyene 23 with Grubbs' ruthenium catalyst in hot CH2Cl2 for 10 h (∼ 30%).
Friedel-Crafts Alkylation with Carbenium Ions Generated by Electrochemical Oxidation of Stannylmethyl Ethers
作者:Anna Lielpetere、Aigars Jirgensons
DOI:10.1002/ejoc.202000568
日期:2020.8.9
Friedel–Crafts alkylation of electron rich arenes can be achieved by stabilized carbenium ions which are generated by single cell anodic oxidation of stannylmethyl ethers at low potential. The use of NaHCO3 as an additive ensures close‐to‐neutral conditions enabling the reaction with arenes bearing acid‐sensitive groups such as O‐TBS, O‐Tr, O‐MOM, O‐THP.