Functional Group Interconversion: The Wang Synthesis of Spirojatamol
Daniele Leonori, now at RWTH Aachen University, employed visible light to promote the Co-catalyzed elimination of the primary bromide 1 to the alkene 2 (J. Am. Chem. Soc. 2021, 143, 14806. ). Yan Xu and Guangbin Dong of the University of Chicago used the hydrazonamide 4 to mediate the deacylative conversion of the ketone 3 to the alkene 5 (J. Am. Chem. Soc. 2021, 143, 20042. ). Jung-Woo Park of KAIST established conditions for converting the internal alkyne 6 to the branched terminal alkenyl silane 7 (ACS Catal. 2021, 11, 12777. ). Gerhard Hilt of the Universität Oldenburg devised electrolytic conditions for the conversion of cyclohexene 8 to the cis 1,2-dichlorocyclohexane 9 (Chem. Eur. J. 2021, 27, 17341. ).
Masahiro Noji and Toshikatsu Takanami of Meiji Pharmaceutical University optimized the rearrangement of the epoxide 10 to the allylic alcohol 11 (Chem. Commun. 2021, 57, 7104. ). Fabio Julía, also of the University of Manchester, and Professor Leonori effected the conversion of the secondary iodide 12 to the primary amine 13 (Nature Catal. 2021, 4, 623. ). Tao Wang and Junkai Fu of Jiangxi Normal University used 15 to selectively demethylate the tertiary amine 14, leading to the amide 16 (Synlett 2021, 32, 1642. ). Kevin Lam of the University of Greenwich prepared the isonitrile 18 by electrolytic oxidation of the aminotetrazole 17 (Org. Lett. 2021, 23, 9371. ).
Qiang Tang of Chongqing Medical University found that sulfuryl chloride smoothly converted the β-keto ester 19 to the 2,2-dichloro ketone 20 (Tetrahedron Lett. 2021, 81, 153335. ). John E. Moses of Cold Spring Harbor Laboratory used a catalytic aminium cation radical to hydrate the eneyne 21 to the enone 22 (Chem. Commun. 2021, 57, 6991. ). Professor Dong used a modified Catellani protocol with the norbornene amide 24 and the N-acyloxy morpholine 25 to convert the enol triflate 23 to the ketone 26, a net 1,2-carbonyl transposition (Science 2021, 374, 734. ). D. Srinivasa Reddy of CSIR-Indian Institute of Integrative Medicine showed that 1,3-transposition of the E-enone 27 led cleanly to the Z-enone 28 (Org. Lett. 2021, 23, 6642. ).
The sesquiterpene spirojatamol (31) was isolated from the roots of Nardostachys jatamansi, a flowering plant of the valerian family that grows in the Himalayas. In the course of a synthesis of 31, Shao-Hua Wang of Lanzhou University achieved remarkable regioselectivity in the conversion of the ketone 29 to the alkene 30 (Tetrahedron Lett. 2021, 85, 153291. ).