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. DOI: 10.1039/D2CC03339A). 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. DOI: 10.1246/cl.220437).
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. DOI: 10.1002/anie.202214610). 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. DOI: 10.1021/acs.orglett.2c02437). 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. DOI: 10.1016/j.tetlet.2022.154137). 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. DOI: 10.1002/anie.202211043).
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. DOI: 10.1002/adsc.202201036). 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. DOI: 10.1038/s41467-022-31453-7). 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. DOI: 10.1002/adsc.202200875). 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. DOI: 10.1039/D2OB00896C).
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. DOI: 10.1002/adsc.202200192). 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. DOI: 10.1021/acs.orglett.2c03494).
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. DOI: 10.1002/anie.202204907).