title: A facile synthesis of natural products chaetomellic acid A and 1,7(Z)- nonadecadiene-2,3-dicarboxylic acid.
abstract: Synthesis of recently isolated bioactive natural products chaetomellic acid A anhydride (1) and a novel 1,7(Z)-nonadecadiene-2,3-dicarboxylic acid (2) have been described. Chemoselective carbon[bond]carbon S(N)2' coupling reactions of appropriate Grignard reagents with dimethyl bromomethylfumarate (7) in diethyl ether in the presence of HMPA at room temperature furnished the corresponding diesters 8 and 15 in 60-62% yields. The formed diesters 8 and 15 on hydrolysis gave respectively the corresponding desired diacids 9 and 2 in quantitative yields. Acetic anhydride induced ring closure of diacids 9 and 2 respectively gave the chaetomellic acid A anhydride (1) and isochaetomellic acid B anhydride (16) with 38-39% overall yields in five steps.
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis*; D002625:Chemistry, Organic / Q000379:methods; D003998:Dicarboxylic Acids / Q000138:chemical synthesis*; D008298:Maleates / Q000138:chemical synthesis*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism
chemical_list: C472226:1,7-nonadecadiene-2,3-dicarboxylic acid; D001688:Biological Products; D003998:Dicarboxylic Acids; D008298:Maleates; C080569:chaetomellic acid A