Abstract
Over the last decade, the use of biocatalysts has become an attractive alternative to conventional chemical methods, especially for organic synthesis, due to their unusual properties. Among these enzymes, lipases are the most widely used, because they are cheap, easily available, cofactor-free, and have broad substrate specificity. Combined to microwave heating in non-aqueous medium, recent results suggest that irradiation may influence the enzyme activity. This Communication reports the benefits of lipases and the microwave irradiation on the kinetic resolution of racemic homochiral (Z)-cyclooct-5-ene-1,2-diol and (Z)-2-acetoxycyclooct-4-enyl acetate. In order to best achieve the kinetic resolution, different parameters were studied including the type of lipase, the temperature, the impact of microwave power compared to conventional heating. Optimization of the reaction parameters lead to the obtainment of highly enriched or enantiopure diols and diesters in a clean, efficient and safe way.
Highlights
Pure vicinal diols are versatile chemical scaffolds for the production of flavors and fragances
In the context of the growing general interest for reducing energy costs, heating chemical reactions under microwave irradiation is a useful approach for achieving higher reaction kinetics and synthesizing cleaner products [10,11,12,13]
In combination with microwave technology and lipases, we wished to examine the synthesis of chiral cyclooctenic diols and diesters starting from cycloocta-1,5-diene using microwave technology. rac-Diols 2 and rac-diacetates 4 were initially prepared from cycloocta-1,5-diene in a three-steps sequence including epoxidation, ring opening with aqueous sulfuric acid, followed by acetylation with acetic anhydride (Scheme 1) [14,15]
Summary
Pure vicinal diols are versatile chemical scaffolds for the production of flavors and fragances. The development of biocatalysts for organic synthesis has become an attractive alternative to conventional chemical methods. Among those biocatalysts, lipases have become very popular in both academic and industrial sectors because they are inexpensive, available, cofactor free and have a broad substrate specificity [1]. Combined to non-aqueous medium, recent results suggest that microwave irradiation can have influence the enzyme stability and activity, in addition to altering/enhancing reaction rates and/or enantioselectivities, called non-thermal microwave effects [2,3,4,5,6,7,8]. We report our studies on microwave assisted lipase resolution of homochiral (1R,2R)- and (1S,2S)-5-cyclooctene1,2-diols 2 and their diesters 4, by varying the irradiation power and reaction temperature
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
