Organic Chemistry Portal
Organic Chemistry Highlights

Monday, February 8, 2016
Douglass F. Taber
University of Delaware

Enantioselective Synthesis of Alcohols and Amines: The Burke Synthesis of (+)-Patulolide C

Richard D. Webster and Yonggui Robin Chi of the Nanyang Technological University described (J. Am. Chem. Soc. 2015, 137, 2416. DOI: 10.1021/ja511371a) a procedure for the enantioselective β-hydroxylation of the enal 1 to the alcohol 2. Bernhard Breit of the Albert-Ludwigs-Universitšt Freiburg used (J. Am. Chem. Soc. 2015, 137, 3131. DOI: 10.1021/jacs.5b01131) a Rh catalyst to prepare 4 by coupling the terminal alkyne 3 with benzoic acid. Sanzhong Luo of the Beijing National Laboratory for Molecular Sciences effected (Org. Lett. 2015, 17, 576. DOI: 10.1021/ol503592n) the enantioselective oxidation of 5 to 7. Hajime Ito of Hokkaido University devised (J. Am. Chem. Soc. 2015, 137, 420. DOI: 10.1021/ja511247z) a protocol for the enantioselective homologation of the aldehyde 8 to the epoxide 9.

Xiaoqi Yu of Sichuan University and Lin Pu of the University of Virginia devised (Chem. Commun. 2015, 51, 358. DOI: 10.1039/C4CC08031A) a simplified procedure for the preparation of propargylic alcohol 11 by the enantioselective addition of the alkyne 3 to the aldehyde 10. Jun-An Ma of Tianjin University reported (J. Org. Chem. 2015, 80, 3766. DOI: 10.1021/jo502741z) the decarboxylative addition of 13 to 12 to give 14. Xiaoming Feng, also of Sichuan University (Chem. Commun. 2015, 51, 10042. DOI: 10.1039/C5CC02748A) and Efraim Reyes and Jose L. Vicario of the University of the Basque Country (Chem. Eur. J. 2015, 21, 8384. DOI: 10.1002/chem.201501044) also reported procedures (not illustrated) for the enantioselective construction of α-hydroxy carbonyl compounds.

Ekaterina M. Budynina and Igor V. Trushkov of Moscow State University reported (Chem. Eur. J. 2015, 21, 4975. DOI: 10.1002/chem.201405551) that the opening of 15 with azide ion delivered 16 with inversion of absolute configuration. P. Andrew Evans of Queen’s University prepared (Chem. Sci. 2015, 6, 777. DOI: 10.1039/C4SC01317D) 18 by the enantioselective amination of 17. Jian Zhang of Shanghai Jiao Tong University converted (Chem. Eur. J. 2015, 21, 120. DOI: 10.1002/chem.201405830) racemic 19 to 20 in high enantiomeric excess. Jeffrey N. Johnston of Vanderbilt University added (Chem. Sci. 2015, 6, 2590. DOI: 10.1039/C5SC00064E) bromonitromethane to the imine equivalent 21 to give an intermediate that after oxidation coupled with the amine 22 to give 23.

Shuichi Nakamura of the Nagoya Institute of Technology added (Chem. Eur. J. 2015, 21, 9066. DOI: 10.1002/chem.201501351) the nitrile 25 to the imine 24 to give the β-amino acid derivative 26. The phenylthio group could be reductively removed without jeopardizing the aminated center. Brian M. Stoltz of Caltech prepared (Angew. Chem. Int. Ed. 2015, 54, 179. DOI: 10.1002/anie.201408609) 28 by the enantioselective rearrangement of 27. He used a similar approach (Org. Lett. 2015, 17, 1082. DOI: 10.1021/ol503425t) to assemble alkylated and oxygenated centers (not illustrated).

(+)-Patulolide C (31), isolated from Penicillium urticae, showed antifungal and antibacterial activity. A key step in the synthesis (J. Org. Chem. 2015, 80, 204. DOI: 10.1021/jo502301k) of 31 by Steven D. Burke of the University of Wisconsin was the preparation of 30 by the enantioselective hydroformylation of 29.

D. F. Taber, Org. Chem. Highlights 2016, February 8.