CAS: 141726-23-0; (4Aα,10α)-3,4,4A,10-Tetrahydro-10-Ethyl-9-Hydroxy-1(2H)-Anthracenone

1-Phenyl-7(Z)-Decene-1,3-Dione置于manganese Triacetate体系中,用 溶剂黄146 用作溶剂,化学反应 20.0H,以58%的收率获得党参粉
参考文献:Control Of The Regioselectivity Of Oxidative Free-Radical Cyclizations By Addition To Haloalkenes
标题:Control Of The Regioselectivity Of Oxidative Free-Radical Cyclizations By Addition To Haloalkenes
摘要:Chlorine Substituents On The Alkene Control The Regioselectivity Of The Cyclization Of 5-Hexenyl Or 6-Heptenyl Radicals Generated By Oxidation Of An Acetoacetate Ester Or 1,3-Diketone With Mn(Oac)3.2H2O. 6-Exo-Cyclization Of The Radicals Obtained By Oxidation Of Benzoylacetone Derivatives 10 And 13,Containing A Chlorine On The Terminal Double Bond Carbon,Gives Alpha-Chloroalkyl Radicals That Add To The Aromatic Ring To Give 11 And 16,Respectively. Loss Of Hcl Leads To Naphthols 8 And 17 Indicating That This Reaction May Be Useful For Aureolic Acid Synthesis. Exo-Cyclization Is The Exclusive Process With Acetoacetates 28B,44,55B,And 59 Containing A Chlorine On The Terminal Double Bond Carbon. 6-Endo-Cyclization Is The Exclusive Process With Acetoacetates 18C And 51B Containing A Chlorine On The Internal Double Bond Carbon. Intra-And Intermolecular Competition Experiments Indicate That These Effects Are Primarily Steric. The Chlorine Substituent Controls The Regioselectivity Of The Cyclization By Sterically Hindering Attack Of The Radical On The Chlorine Bearing Double Bond Carbon Thereby Retarding Formation Of The Beta-Chloroalkyl Radical. The Chlorine Substituent Does Not Electronically Accelerate Attack On The Other End Of The Double Bond To Give The Alpha-Chloroalkyl Radical.
Doi:10.1021/jo00041A026