Arrays of Stereogenic Centers: The Hu Synthesis of Ileabethoxazole

Alfonso Polo and Miquel Costas of the Universitat de Girona devised a Mn catalyst for the epoxidation of 1 to 2 (Org. Lett. 2019, 21, 2430. DOI: 10.1021/acs.orglett.9b00729). William D. Wulff of Michigan State University used a VANOL-derived borate catalyst to mediate the Darzens-like addition of 4 to 3 to give 5 (Angew. Chem. Int. Ed. 2019, 58, 3361. DOI: 10.1002/anie.201809511). Victorio Cadierno of the Universidad de Oviedo and Antonio Pizzano of CSIC-Universidad de Sevilla effected the enantioselective hydrogenation of 6 to 7 (Chem. Commun. 2019, 55, 786. DOI: 10.1039/C8CC09391A). M. Christina White of the University of Illinois showed that depending on the choice of ligand, the oxidative cyclization of 8 could be directed to give either diastereomer of 9 (J. Am. Chem. Soc. 2019, 141, 9468. DOI: 10.1021/jacs.9b02690).

Nuno Maulide of the University of Vienna demonstrated that the FeCl₃-catalyzed addition of 11 to 10 was followed by diastereoselective intramolecular hydride transfer, leading to 12 (J. Am. Chem. Soc. 2019, 141, 143, DOI: 10.1021/jacs.8b12242; Angew. Chem. Int. Ed. 2019, 58, 5887, DOI: 10.1002/anie.201900801). Amir Hoveyda of Boston College established conditions for the reductive addition of 14 to 13 to give 15 (Science 2019, 364, 45. DOI: 10.1126/science.aaw4029). Xin Hong of Zhejiang University and Pu-Sheng Wang and Liu-Zhu Gong of the University of Science and Technology of China effected the oxidative Pd-catalyzed coupling of 16 with 17 to give 18 (J. Am. Chem. Soc. 2019, 141, 5824. DOI: 10.1021/jacs.8b13582). Donald A. Watson of the University of Delaware assembled 22 by combining methyl acrylate 21 with the product from the addition of 20 to 19 (J. Am. Chem. Soc. 2019, 141, 8436. DOI: 10.1021/jacs.9b04175).

Jean Rodriguez and Yoann Coquerel of Aix Marseille Université used a Cinchona alkaloid derived catalyst to effect the addition of 23 to 24, to give an adduct that underwent ring expansion to 25 (Angew. Chem. Int. Ed. 2019, 58, 456. DOI: 10.1002/anie.201810184). Santanu Mukherjee of the Indian Institute of Science, Bangalore employed a Hayashi-Jørgensen catalyst to direct the Michael addition of 26 to 27, leading after reduction to the alcohol 28 (J. Org. Chem. 2018, 83, 12071. DOI: 10.1021/acs.joc.8b02051). Todd K. Hyster of Princeton University showed that a photoexcited flavoenzyme could mediate the cyclization of 29 to 30 (Science 2019, 364, 1166. DOI: 10.1126/science.aaw1143). Yi-Feng Wang and Dan-Qian Xu of the Zheliang University of Technology also used a Cinchona alkaloid derived catalyst to assemble 33 by combining 31 with 32 (Org. Chem. Front. 2019, 6, 1140. DOI: 10.1039/C9QO00011A).

Ileabethoxaxole (37), isolated from the Caribbean sea ship Pseudopterogorgia elisabethae, shows significant activity against Mycobacterium tuberculosis. En route to 37, Xiangdong Hu of Northwest University used the Carreira strategy to set two of the four stereogenic centers, coupling 35 with racemic 34 to give 36 in high ee (Angew. Chem. Int. Ed. 2019, 58, 7845. DOI: 10.1002/anie.201901651).