Monday, May 8, 2023
Douglass F. Taber
University of Delaware
C-O Ring Construction: The Liu/Wang Synthesis of Miharimycin B
Mark G. McLaughlin of the University of Lancaster found that under alkaline conditions, the alcohol 1 could be cyclized to the iodo oxetane 2 (Chem. Commun. 2022, 58, 8376. ). Yutaka Ukaji of Kanazawa University observed high asymmetric induction in the [2+2] photocycloaddition of the α-keto ester 3 with furfuryl alcohol 4 to give the oxetane 5 (Chem. Lett. 2022, 51, 1143. ).
Jared C. Lewis of Indiana University showed that a flavin-dependent halogenase could cyclize the alcohol 6 to the tetrahydrofuran 7 in high ee (Angew. Chem. Int. Ed. 2022, 61, e202214610. ). Yong Jian Zhang of Shanghai Jiao Tong University combined the enone 8 with the racemic epoxide 9 to give the tetrahydrofuran 10 in high ee (Org. Lett. 2022, 24, 6716. ). Matthias Brewer of the University of Vermont observed high diastereoselectivity in the assembly of the tetrahydrofuran 13 by coupling the silyl enol ether 12 wih the α-diazo ester 11 (Tetrahedron Lett. 2022, 109, 154137. ). Shi-Jun Li of Zhengzhou University, Yu Lan of Chongqing University, and Quanquan Wang and Ming Joo Koh of the National University of Singapore devised the three-component coupling of the glycosyl chloride 14, the iodoarene 15 and isobutyl chloroformate to prepare the C-acyl glycoside 16 (Angew. Chem. Int. Ed. 2022, 62, e202211043. ).
Bhoopendra Tiwari of the Centre of Biomedical Research used a triazolium NHC catalyst to mediate the coupling of the α-selenyl enone 17 with cinnamaldehyde 18 to give the enol lactone 19 (Adv. Synth. Catal. 2022, 364, 4031. ). Tingshun Zhu of Sun Yat-sen University used the same triazolium NHC catalyst to prepared the enol lactone 22 by combining the chalcone 20 with butanal 21 (Nature Commun. 2022, 13, 3827. ). Zheng-Hang Qi of the University of Science and Technology of China and Yong Wang and Xing-Wang Wang of Soochow University devised the hetero Diels-Alder addition of the α-keto ester 23 to cyclopentadiene 24, leading to the bicyclic 25 (Adv. Synth. Catal. 2022, 364, 4347. ). Pei-Xin Rui and Xiang-Guo Hu of Jiangxi Normal University showed that the alkenyl glycoside 26 could be cleanly oxidized to the glycosyl carboxylic acid 27 (Org. Biomol. Chem. 2022, 20, 5452. ).
Ai-Jun Ma of Wuyi University effected the oxidative ring expansion of the cyclopentanone 28 to the macrolactone 29 (Adv. Synth. Catal. 2022, 364, 2152. ). Hyoungsu Kim of Ajou University cyclized the tartrate-derived bis-tosylate 30 to the bicyclic amide 31 with high diastereocontrol (Org. Lett. 2022, 24, 8780. ).
Miharimycin B (34), isolated from Streptomyces miharaensis, inhibited the growth of the plant pathogenic fungus Pyricularia oryzae at 10-20 ppm. Jian Liu and Xiaolei Wang of Lanzhou University assembled the trans 6/5 bicyclic core of 34 by the MsCl-mediated cyclization of the carbohydrate-derived polyol 32 to 33 (Angew. Chem. Int. Ed. 2022, 61, e202204907. ).
D. F. Taber, Org. Chem. Highlights 2023, May 8.