126255-88-7Relevant academic research and scientific papers
Thermal Diels-Alder Reactions with N-(2-Alkenoyl)-(S)-proline Esters as Chiral Dienophils
Waldmann, Herbert,Draeger, Martin
, p. 681 - 685 (2007/10/02)
Cyclopentadiene reacts with N-acryloyl-(S)-proline benzyl and allyl ester in toluene at 0 deg C to give the bicycloheptenecarboxylic acid amides with a stereoselection of (2S):(2R) = 81:19.In the reactions with the N,N'-fumaroylbis(proline esters) the cycloadducts are formed in high yields and with isomer ratios of up to 97:3.The absolute configuration of N,N'-hept-5-ene-2,3-diyldicarbonyl>bis- (6a) has been determined by an X-ray analysis.In the reactions of the acrylamides with cyclopentadiene and of the furmaramides with cyclopentadiene, isoprene and 2,3-dimethylbutadiene the use of water/ethanol mixtures as solvent, if indicated in the presence of detergents, doubles the yields.However, a positive influence of the aqueous medium on the diastereomeric ratio can not be observed.
Amino Acid Esters as Chiral Auxiliaries in Lewis Acid Catalyzed Diels-Alder Reactions
Waldmann, Herbert
, p. 671 - 680 (2007/10/02)
Cylopentadiene, cyclohexadiene and alkyl-substituted butadienes react with N-acryloyl-, N-crotonoyl- and N-(4-nitrocinnamoyl)-(S)-proline benzyl and allyl ester in the presence of Lewis acids to give the cycloadducts in high yields and with stereoselectiv
ON THE ENHANCEMENT OF STEREOSELECTION BY COOPERATION BETWEEN CHIRAL AUXILIARIES. ASYMMETRIC DIELS-ALDER REACTIONS WITH FUMARIC ACID BIS((S)-PROLINE BENZYL ESTER) AMIDE
Waldmann, H.,Draeger, M.
, p. 4227 - 4230 (2007/10/02)
Fumaric acid bis((S)-proline benzyl ester) amide reacts with cyclopentadiene in thermal and Lewis acid catalyzed Diels-Alder reactions to give cycloadducts with high yields and diastereomeric ratios up to 100:1.
