117775-66-3Relevant academic research and scientific papers
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
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.
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.
