65756-85-6Relevant academic research and scientific papers
Diels-Alder Additions to 1-Phenyl-2-benzopyran-3-one and Transformations of the Adducts: Model Experiments for Podophyllotoxin Synthesis
Jones, David W.
, p. 399 - 406 (2007/10/02)
1-Phenyl-2-benzopyran-3-one 2 adds to a series of unsymmetrically substituted dienophiles (methyl acrylate, ethyl crotonate, methyl ω-bromocrotonate, and crotonaldehyde) with regioselectivity largely determined by the phenyl group but with little endo-exo
Synthesis of (+/-)-4-Deoxypodophyllotoxin, (+/-)-Podophyllotoxin and (+/-)-Epipodophyllotoxin
Jones David W.,Thompson, Adrian M.
, p. 2541 - 2548 (2007/10/02)
6,7-Methylenedioxy-1-(3',4',5'-trimethoxyphenyl)-2-benzopyran-3-one 1 and dimethyl fumarate in acetonitrile give mostly the C-2 exo-CO2Me adduct 4 which is transformed in four steps into epipodophyllotoxin 10a.Attempted addition of dimethyl maleate to 1 p
Regioselective Suprafacial 1,5-Hydrogen Shifts in o-Quinodimethanes; a Route to 4-Deoxypodophyllotoxin
Jones, David W.,Thompson, Adrian M.
, p. 1095 - 1096 (2007/10/02)
The o-quinodimethane intermediate (4a) with cis-CO2Me groups undergoes regioselective 1,5-hydrogen shift to the cis-dihydronaphthalene (5a) whilst its trans-isomer (9a) gives both 1,5-hydrogen shift products (6a) and (7a); (5a) is readily converted into 4
E,E- and E,Z-α-phenyl-α'-acetoxyorthoquinodimethane: steric and electronic control of cycloaddition reactions
Charlton, James L.,Alauddin, Mian M.,Penner, Glenn H.
, p. 793 - 798 (2007/10/02)
E,E- and E,Z-α-phenyl-α'-acetoxyorthoquinodimethanes have been prepared from the corresponding cis- and trans-1-acetoxy-3-phenyl-1,3-dihydrobenzothiophene-2,2-dioxides.The regio- and diastereoselectivity of the addition reactions with dimethyl fumarate, dimethyl maleate, maleic anhydride, and methyl crotonate have been determined.Ab initio calculations have been carried out on orthoquinodimethane and its α-phenyl and α-oxy derivatives.A correlation has been made between the steric and electronic properties of the orthoquinodimethanes and the regio- and diastereoselectivity of their Diels-Alder reactions.
