Stereoselective Enzymatic Synthesis of cis‐Pellitorine, a Taste Active Alkamide Naturally Occurring in Tarragon

• Published in: European Journal of Organic Chemistry
• Main Authors: Ley, Jakob P., Hilmer, Jens‐Michael, Weber, Berthold, Krammer, Gerhard, Gatfield, Ian L., Bertram, Heinz‐Jürgen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2004
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1002/ejoc.200400403; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fejoc.200400403; https://onlinelibrary.wiley.com/doi/full/10.1002/ejoc.200400403

Abstract The alkamide cis ‐pellitorine [(2 E ,4 Z )‐ N ‐isobutyldeca‐2,4‐dienamide] that occurs naturally in tarragon was prepared in yields up to 80% by lipase‐catalyzed conversion of ethyl 2 E ,4 Z ‐decadienoate, the so‐called pear ester, and isobutylamine both with and without the use of cosolvents. Of 13 different commercial enzyme preparations tested (lipases, proteases, esterases), only the lipase type B from Candida antarctica has a suitable activity. The reaction of the different geometric isomers of ethyl 2,4‐decadienoate to the appropriate pellitorines shows a remarkable selectivity: the 2 E ,4 Z ester is converted between 1.4 and 3.9 times faster than the 2 E ,4 E isomer, and the relative yield of cis ‐pellitorine compared with trans ‐pellitorine is 5.7 to 16.3 times higher. In contrast to the better known trans ‐pellitorine, which at 10 ppm is only slightly tingling and numbing, cis ‐pellitorine shows very interesting pungent and warming sensations after tasting trials already in low concentrations of 10 ppm. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)