117970-68-0Relevant academic research and scientific papers
Synthesis of Highly Functionalized Flavones and Chromones Using Cycloacylation Reactions and C-3 Functionalization. A Total Synthesis of Hormothamnione
McGarry, Lynda W.,Detty, Michael R.
, p. 4349 - 4356 (2007/10/02)
The cycloacylations of hydroxy- and methoxy-substituted phenols with aryl- and alkylpropiolic acids using Eaton's reagent (10percent phosphorus pentoxide in methanesulfonic acid) gives highly substituted flavones and chromones in up to 63 percent yield.Styrylchromones were prepared from 2-methylchromones by condensation reactions of the 2-methyl group with various substituted benzaldehydes in sodium ethoxide and ethanol in almost quantitative yield.Methylation or hydroxylation at C-3 of these highly substituted flavones and styrylchromones was accomplished in a highly regioselective manner employing lithium diisopropylamide followed by quenching with an electrophile.Quenching of the initial anion with methyl triflate gave 3-methyl products while quenching of the initial anion with trimethylborate followed by oxidation gave 3-hydroxy products.A total synthesis of the naturally occurring styrylchromone hormothamnione, containing a 3-methyl substituent, is reported by use of these synthetic techniques.
SYNTHESIS OF HORMOTHAMNIONE
Alonso, Ricardo,Brossi, Arnold
, p. 735 - 738 (2007/10/02)
Hormothamnione 1 has been obtained from 2,3-dimethyl-5,6,7,8-tetramethoxy-chromone 18 in 63percent yield.Synthesis of the required chromone 18 as well as of the 2 and 3-styryl analogs 5 and 9 are described.
