92180-15-9

Upstream product

• 2345-61-1 (E)-3-chloroacrylic acid 
• 2216-51-5 (-)-menthol 

Downstream Products

• 92180-27-3 (3R,4R)-4-Isopropenyl-3-((1S,2R,5S)-2-isopropyl-5-methyl-cyclohexyloxycarbonylmethyl)-1-(2,2,2-trifluoro-acetyl)-pyrrolidine-2,2-dicarboxylic acid diethyl ester 
• 92180-27-3 menthyl trans-(2,2-diethoxycarbonyl-4-isopropenyl-1-trifluoroacetylpyrrolidin-3-yl)acetate 
• 77632-78-1 (-)-menthyl(E)-4,4-diethoxycarbonyl-4--2-butenoate 
• 92180-18-2 (-)-menthyl(E)-4,4-diethoxycarbonyl-4-trifluoroacetamido-2-butenoate 

Relevant academic research and scientific papers

ENANTIOSELECTIVE SYNTHESIS OF (+)-α-ALLOKAINIC ACID BY ASYMMETRIC LEWIS ACID-MEDIATED INTRAMOLECULAR ENE REACTION

(+)-α-Allokainic acid ((+)-1) has been prepared for the ester of cis-β-chloroacrylic acid and (-)-8-phenylmenthol by a sequence of four synthetic operations.The crucial step 8d-14d (Scheme 4) is a 100percent diastereo- and 90percent enantioselective intramolecular ene reaction proceeding at -35 degC on treatment of 8d with Me2AlCl.Saponification of 14d regenerated the auxiliary chiral alcohol and yielded (+)-1 on subsequent decarboxylation.In the analogous cyclization 11d-15d the sense of asymmetric induction (78percent d.e.) was opposite as confirmed by the conversion of 15d to (-)-α-allokainic acid.

High Asymmetric Induction in Lewis Acid-Promoted Intramolecular Ene-Type Reactions: A Diastereo- and Enantioselective Synthesis of (+)-α-Alolokainic Acid

The monocyclic amino diacid (+)-α-allokainic acid 1 has been prepared enantioselectively from the ester of cis-β-chloroacrylic acid and (-)-8-phenylmenthol by a series of four synthetic operations in over 15percent yield.The crucial step is the intramolecular 'ene-type' reaction of the (Z)-diene 4 which on treatment with a mild Lewis acid undergoes a highly accelerated, dia- and enantiostereoselective cyclization to give the pyrrolidines 6 and 7 in a ratio of 95:5 (Scheme 3).Subsequent ester hydrolysis regenerates the auxiliary chiral alcohol.Similar cyclization of the (E)-diene 5 furnished a 15:85 mixture of 6 and 7 showing an efficient reversal of the optical induction by variation of the enoate geometry.