Synthesis of the Oxygenated Bicyclo[9.3.1]pentadecane Ring System of Phomactin A using Chromium (II)-mediated Macrocyclisation and Ring Closure Metathesis

All articles of this category Treatment of the aldehyde vinyl iodides 17, 19 a and 19 b in DMSO with CrCl 2 -NiCl 2 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 CH 2 Cl 2 for 10 h (∼ 30%). macrocyclisation - chromium (II) - phomactin A - metathesis - PAF