Improved synthesis for the rodenticides, diphenacoum and brodifacoum
作者:Pieter S. van Heerden、Barend C. B. Bezuidenhoudt、Daneel Ferreira
DOI:10.1039/a607269k
日期:——
An improved synthesis of the 3-[3-(p-substituted
phenyl)-1,2,3,4-tetrahydro-1-napththyl]-4-hydroxycoumarins, diphenacoum
and brodifacoum, is described. The process is primarily based on the
formation of one of the crucial bonds in the carbon backbone using
organocopper methodology, and on the coupling of the 4-hydroxycoumarin
moiety to the 3-biphenyl tetralin unit under strongly acidic
conditions.
rodenticide in racemic form, is performed using a key step of rhodium catalyzed enantioselective intramolecular hydroacylation. Optimization of the last step, condensation of 4-hydroxycoumarin with chiral 3-([1,1′-biphenyl]-4-yl)-1,2,3,4-tetrahydronaphthalen-1-ol, is also discussed. After chromatographic separation of the cis and trans diastereoisomers, the four stereoisomers were all obtained with