Organic Chemistry Portal
Organic Chemistry Highlights

Monday, June 24, 2024
Douglass F. Taber
University of Delaware

Functional Group Interconversion: The Maier Synthesis of Berkeylactone A

Osama El-Sepelgy of the Leibniz Institute for Catalysis e.V., Rostock observed high regioselectivity in the photochemically-promoted elimination of the Katrizky salt 1 to the alkene 2 (ACS Catal. 2023, 13, 14205. DOI: 10.1021/acscatal.3c04305). Léon Ghosez of the University of Bordeaux also achieved high regioselectivity in the reaction of the 1,3-dione 3 with the chloroenamine 4 to give the chloroenone 5 (Synthesis 2023, 55, 2083. DOI: 10.1055/a-2017-4685). Shou-Fei Zhu of Nankai University achieved high geometric control in the assembly of the allylsilane 7 from the diene 6 (Angew. Chem. Int. Ed. 2023, 62, e202315473. DOI: 10.1002/anie.202315473). Martin Oestreich of the Technische Universität Berlin developed a general strategy for the construction of dialkyl dimethylsilanes, as illustrated by the chlorodemethylation of the trimethylsilane 8 with dichloroethane 9 followed by coupling with the lithium acetylide 10, leading to 11 (Nature 2023, 623, 538. DOI: 10.1038/s41586-023-06646-9).

Chaunle Zhu of the South China University of Technology activated the alcohol 12 by coupling with the 1,1-difluoroalkene 13 followed by displacement with the sulfonamide 14, to give the protected amine 15 with clean inversion of absolute configuration (Org. Lett. 2023, 25, 5431. DOI: 10.1021/acs.orglett.3c01713). Zhi Wang and Lei Wang of Jilin University and Chuang Du of the Changchun Institute of Applied Chemistry prepared the isothiocyanate 17 by coupling the amine 16 with carbon disulfide (Org. Lett. 2023, 25, 5692. DOI: 10.1021/acs.orglett.3c02193). Jonathan A. Ellman of Yale University equilibrated the axial amine 18 to the equatorial amine 19 (Org. Lett. 2023, 25, 9197. DOI: 10.1021/acs.orglett.3c03801). Esteban Mejía, also of the Leibniz Institute for Catalysis, reduced the carbamate 20 to the dimethyl amine 21 (Eur. J. Org. Chem. 2023, 26, e202300904. DOI: 10.1002/ejoc.202300904).

Darren J. Dixon of the University of Oxford devised a protocol for converting the amide 22 to the α-amino ketone 23 (J. Am. Chem. Soc. 2023, 145, 21745. DOI: 10.1021/jacs.3c08466). Benjamin N. Bhawal and Bill Morandi of ETH Zürich converted the dione 24 to the more stable dione 25 (J. Am. Chem. Soc. 2023, 145, 19496. DOI: 10.1021/jacs.3c05680).

Chuanle Zhu of the South China Institute of Technology also prepared the ortho ester 28 by reacting the trifluoromethyl alkene 26 with trifluoroethanol 27 (Chem. Commun. 2023, 59, 8238. DOI: 10.1039/D3CC01760E). Jing Li of Xi'an Jiaotong University coupled the nitroalkane 29 with the amine 30, leading to the thioamide 31 (Nature Commun. 2023, 14, 4626. DOI: 10.1038/s41467-023-40334-6).

Berkeleylactone A (35), isolated from Penicillium turbatum, showed potent antimicrobial activity. Taking advantage of the "inside/outside" geometry of medium rings, Martin E. Maier of Eberhard Karls Universität Tübingen achieved high diastereoselectivity in the conjugate addition of the thiol 33 to the enone 32, leading to 34 (Eur. J. Org. Chem. 2023, 26, e202300615. DOI: 10.1002/ejoc.202300615).

D. F. Taber, Org. Chem. Highlights 2024, June 24.