Reduction: The Barriault Synthesis of Salvinorin A

Chau Ming So of the Hong Kong Polytechnic University selectively reduced the chloride of 1 with octadeutero-2-propanol 2, leading to the aryl triflate 3 (Org. Lett. 2023, 25, 8429. DOI: 10.1021/acs.orglett.3c03281). Xu Cheng of Nanjing University reduced the trifluoromethyl group of 4 to the trideutero methyl group of 5 (Org. Lett. 2023, 25, 5602. DOI: 10.1021/acs.orglett.3c01942). Jin-Hong Lin of Shanghai University, Qu-Tong Zheng of the Hunan University of Chinese Medicine and Ji-Chang Xiao of the Shanghai Institute of Organic Chemistry used diiodoethane 7 to deoxygenate the alcohol 6, leading to 8 (Org. Biomol. Chem. 2023, 21, 8989. DOI: 10.1039/D3OB01698F). Weisi Guo of the Qingdao University of Science and Technology developed the electrochemical deoxygenation of the alcohol 9 to give 10 (Synthesis 2023, 55, 2993. DOI: 10.1055/a-2013-5865).

Xuesong Wu of the Huazhong University of Science and Technology used CS₂ to activate the alcohol 11 for deoxygenation to 12 (Org. Lett. 2023, 25, 6571. DOI: 10.1021/acs.orglett.3c02432). Lívia N. Cavalcanti of the Federal University of Rio Grande do Norte devised a practical protocol for the photochemically-promoted decarboxylation of the acid 13 to the hydrocarbon 14 (Chem. Eur. J. 2023, 29, e202302330. DOI: 10.1002/chem.202302330).

Aishun Ding of the Shanghai Institute of Applied Physics and Hao Guo of Fudan University developed the photochemically-driven reduction of the conjugated alkene 15 to the ester 16 (Org. Lett. 2023, 25, 7633. DOI: 10.1021/acs.orglett.3c02920). D. Srinivasa Reddy of the National Chemical Laboratory, Pune reduced the diol 17 to the conjugated alkene 18 (J. Org. Chem. 2023, 88, 14227. DOI: 10.1021/acs.joc.3c01613).

Jordi Burés of the University of Manchester and Joseph Cornella of the Max-Planck-Institut für Kohlenforschung used a bismuth catalyst to reduce the amide 19 to the amine 20 (Angew. Chem. Int. Ed. 2023, 62, e202306447. DOI: 10.1002/anie.202306447). Ran Hong, also of the Shanghai Institute of Organic Chemistry, showed that Dibal could be used to reduce even the sensitive ester 21 to the aldehyde 22 (ACS Cent. Sci. 2023, 9, 84. DOI: 10.1021/acscentsci.2c01096). P. Veeraraghavan Ramachandran of Purdue University demonstrated that TiCl₄ promoted the reduction of the ester 23 to the ether 24 (Org. Lett. 2023, 25, 6902. DOI: 10.1021/acs.orglett.3c02643). Dexi Yang, Christopher H. Schuster and Dipannita Kalyani of Merck achieved high equatorial diastereoselectivity in the reductive coupling of the ketone 25 with the alcohol 26, leading to the ether 27 (J. Org. Chem. 2023, 88, 13454. DOI: 10.1021/acs.joc.3c00822).

Salvinorin A (30), isolated from the leaves of the Mexican mint Salvia divinorum, is a potent κ opioid receptor agonist. En route to 30, Louis Barriault of the University of Ottawa showed that the SmI₂-mediated reduction of the unsaturated ester 28 delivered predominantly the desired equatorial product 29 (Chem. Eur. J. 2023, 29, e202301640. DOI: 10.1002/chem.202301640).