Arrays of Stereogenic Centers: The Tanaka/Kitamura Synthesis of Pancratistatin
Jin Kun Cha of Wayne State University achieved high diastereoselectivity in the reductive addition of the propargyl ether 1 to the aldehyde 2, to give the 1,6-diol 3 (Org. Lett. 2022, 24, 6252. DOI: 10.1021/acs.orglett.2c02258). Chun-Jiang Wang of Wuhan University effected conjugate addition of 5 to the enone derived from the allylic alcohol 4, leading after in situ reduction to the 1,4-amino alcohol 6 in high ee (Angew. Chem. Int. Ed. 2022, 61, e202206517. DOI: 10.1002/anie.202206517). Ya-Qiu Long of Soochow University prepared the protected 1,5-diol 7 by the enantioselective oxidation of the β-keto ester 7 (Chem. Commun. 2022, 58, 13447. DOI: 10.1039/D2CC04529J). Ke-Qiang Hou and Xiao-Feng Xiong of Sun Yat-sen University used (DHQD)2PHAL to mediate the construction of the 1,2-diamine 11 by the addition of the protected α-amino acid 9 to the ene sulfonamide 10 (J. Org. Chem. 2022, 87, 8709. DOI: 10.1021/acs.joc.2c00950).
Todd K. Hyster of Cornell University used a combination of enzymes to reduce the lactone 12 to the alcohol 13 (Org. Process Res. Dev. 2022, 26, 2096. DOI: 10.1021/acs.oprd.2c00017). Alois Fürstner of the Max-Planck-Institut für Kohlenforschung achieved high ee in the preparation of the alcohol 16 by the 1,2-addition of the dienyl amide 15 to the aldehyde 14 (J. Am. Chem. Soc. 2022, 144, 18817. DOI: 10.1021/jacs.2c09328). Zhongxing Huang of the University of Hong Kong converted the prochiral β-diketone 17 into the cyanohydrin 18 (Angew. Chem. Int. Ed. 2022, 61, e202208443. DOI: 10.1002/anie.202208443). Jisheng Luo and Li Deng of Westlake University used a Cinchona-derived diamine to prepare 21 by the addition of the lactone 20 to the imine 19 (JACS Au 2022, 2, 2678. DOI: 10.1021/jacsau.2c00465).
Helma Wennemers of ETH Zürich used a tripeptide to catalyze the enantioselective addition of the aldehyde 22 to the nitroalkene 23, to give 24 (Adv. Synth. Catal. 2022, 364, 3354. DOI: 10.1002/adsc.202200576). Xile Hu of the Ecole Polytechnique Fédérale de Lausanne added the α-bromolactam 26 to the alkenyl borane 25, leading, after the addition of vinyl magnesium bromide, to the alkene 27 (Nature Catal. 2022, 5, 1180. DOI: 10.1038/s41929-022-00894-0). K. N. Houk of UCLA and Yifeng Chen of the East China University of Science & Technology described the assembly of the lactam 30 by the coupling of the amide 28 with the alkyl iodide 29 (Angew. Chem. Int. Ed. 2022, 61, e202207536. DOI: 10.1002/anie.202207536). Yangbin Liu of Shenzhen Bay Laboratory and Xiaoming Feng of Sichuan University constructed the vicinal quaternary stereogenic centers of the oxindole 33 by the alkylation of the lactam 32 with the allylic alcohol 31 (Angew. Chem. Int. Ed. 2022, 61, e202208837. DOI: 10.1002/anie.202208837).
Pancratistatin (37), isolated from the bulbs of the Hawaiian spider lily Hymenocallis littoralis, shows significant anticancer activity. Shinji Tanaka of AIST and Masato Kitamura of Nagoya University alkylated the β-keto ester 35 with the allylic alcohol 34, leading after reduction to the alcohol 36, having three of the six stereogenic centers of 37 (Nature Commun. 2022, 13, 5876. DOI: 10.1038/s41467-022-33432-4).