High Pressure Diels−Alder Approach to Hydroxy-Substituted 6a-Cyano-tetrahydro-6H-benzo[c]chromen-6-ones: A Route to Δ<sup>6</sup>-<i>Cis</i>-Cannabidiol
作者:Eleonora Ballerini、Lucio Minuti、Oriana Piermatti、Ferdinando Pizzo
DOI:10.1021/jo9005365
日期:2009.6.5
Diels-Alder cycloaddition reactions of 3-cyanocoumarin, hydroxy-substituted 3-cyanocoumarins and mesyl-substituted 3-cyano-coumarins with methyl-1,3-butadienes carried out under high pressure (11 kbar) are reported. Activation by high pressure allows these reactions to proceed satisfactorily under mild conditions to produce 6a-cyano-hydroxy- and 6a-cyano-mesyl-tetrahydro-6H-benzo[c]chromen-6-ones in moderate to excellent yield. The synthesis of cis-1-hydroxy-9-methyl-3-pentyl-6a,7, 10,10a-tetrahydro-benzo[c]chromen-6-one as precursor of Delta(6)-3,4-cis-cannabidiol (Delta(6)-cis-CBD) and Delta(8)-cis-tetrahydrocannabinol (Delta(8)-cis-THC) is outlined.