85960-57-2Relevant academic research and scientific papers
The rational design of modified Cinchona alkaloid catalysts. Application to a new asymmetric synthesis of chiral chromanes
Merschaert, Alain,Delbeke, Pieter,Daloze, Désiré,Dive, Georges
, p. 4697 - 4701 (2004)
A new asymmetric synthesis of 2-substituted chiral chromanes has been achieved. The key step is the intramolecular conjugate addition of a phenolic nucleophile on a α,β-unsaturated ester catalyzed by Cinchona alkaloids. The high ee's obtained with cinchonine and its derivatives have been rationalized by ab initio quantum chemistry calculations of transition state structures.
Tandem Wessely oxidation and intramolecular Diels-Alder reactions. III. Synthesis of isotwistanes
Yates, Peter,Macas, Tadas S.
, p. 1 - 10 (2007/10/02)
Wessely oxidation of o-(3-alkenyl) phenols (5) with lead tetraacetate gives 6-acetoxy-6-(3-alkenyl)-2,4-cyclohexadien-1-ones (6), which undergo intramolecular Diels-Alder reactions to give isotwistene (hexahydro-1,5-methanoindene) derivatives (7).These, on hydrolysis followed by oxidation with periodic acid, give hexahydro-1-oxo-1H-indene-5-carboxylic acids (41, 46).Compounds 5 were prepared either by Grignard coupling of o-methoxybenzyl chloride with allyl halides followed by de-O-methylation with sodium thioethoxide or via reduction of dihydrocoumarins (18-20) to 2-chromanols (21-23) with diisobutylaluminum hydride, followed by Wittig reaction of these with ethyl (triphenylphosphoranylidene)acetate.
A GENERAL SYNTHESIS OF ISOTWIST-8-EN-2-ONES FROM o-(3-BUTENYL)PHENOLS
Macas, Tadas S.,Yates, Peter
, p. 147 - 150 (2007/10/02)
Wessely oxidation of o-(3-butenyl)phenols with lead tetraacetate gives 2,4-cyclohexadienone derivatives that on heating undergo intramolecular Diels-Alder reactions to give 3-acetoxyisotwist-8-en-2-ones.
