Organic Chemistry Portal
Organic Chemistry Highlights

Monday, July 25, 2011
Douglass F. Taber
University of Delaware

Establishing Arrays of Stereogenic Centers: The Sato/Chida Synthesis of (-)-Kainic Acid

Benjamin List of the Max-Planck-Institut, Mülheim devised (J. Am. Chem. Soc. 2010, 132, 10227. DOI: 10.1021/ja1037935) a catalyst system for the stereocontrolled epoxidation of a trisubstituted alkenyl aldehyde 1. Takashi Ooi of Nagoya University effected (Angew. Chem. Int. Ed. 2010, 49, 7562; DOI: 10.1002/anie.201004072 see also Org. Lett. 2010, 12, 4070, DOI: 10.1021/ol101658n) enantioselective Henry addition to an alkynyl aldehyde 3. Madeleine M. Joullié of the University of Pennsylvania showed (Org. Lett. 2010, 12, 4244. DOI: 10.1021/ol101584z) that an amine 7 added selectively to an alkynyl aziridine 6. Yutaka Ukaji and Katsuhiko Inomata of Kanazawa University developed (Chem. Lett. 2010, 39, 1036. DOI: 10.1246/cl.2010.1036) the enantioselective dipolar cycloaddition of 9 with 10.

K. C. Nicolaou of Scripps/La Jolla observed (Angew. Chem. Int. Ed. 2010, 49, 5875, DOI: 10.1002/anie.201003500; see also J. Org. Chem. 2010, 75, 8658, DOI: 10.1021/jo101519t) that the allylic alcohol from enantioselective reduction of 12 could be hydrogenated with high diastereocontrol. Masamichi Ogasawara and Tamotsu Takahashi of Hokkaido University added (Org. Lett. 2010, 12, 5736. DOI: 10.1021/ol102554a) the allene 14 to the acetal 15 with substantial stereocontrol. Helen C. Hailes of University College London investigated (Chem. Comm. 2010, 46, 7608. DOI: 10.1039/C0CC02911D) the enzyme-mediated addition of 18 to racemic 17. Dawei Ma of the Shanghai Institute of Organic Chemistry, in the course of a synthesis of oseltamivir (Tamiflu), accomplished (Angew. Chem. Int. Ed. 2010, 49, 4656. DOI: 10.1002/anie.201001644) the enantioselective addition of 21 to 20.

Shigeki Matsunaga of the University of Tokyo and Masakatsu Shibasaki of the Institute of Microbial Chemistry developed (Org. Lett. 2010, 12, 3246. DOI: 10.1021/ol101185p) a Ni catalyst for the enantioselective addition of 23 to 24. Juthanat Kaeobamrung and Jeffrey W. Bode of ETH-Zurich and Marisa C. Kozlowski of the University of Pennsylvania devised (Proc. Natl. Acad. Sci. 2010, 107, 20661. DOI: 10.1073/pnas.1016087107) an organocatalyst for the enantioselective addition of 27 to 26. Yihua Zhang of China Pharmaceutical University and Professor Ma effected (Tetrahedron Lett. 2010, 51, 3827. DOI: 10.1016/j.tetlet.2010.05.077) the related addition of 27 to 29.

There have been scattered reports on the stereochemical course of the coupling of cyclic secondary organometallics. In a detailed study, Paul Knochel of Ludwig-Maximilians-Universität München showed (Nature Chem. 2020, 2, 125. DOI: 10.1038/nchem.505) that equatorial bond formation dominated, exemplified by the conversion of 31 to 33.

A classic strategy for establishing arrays of contiguous stereogenic centers has been to effect stereocontrolled allylic coupling, beginning with a carbohydrate precursor. This is elegantly exemplified by the synthesis of (-)-Kainic Acid 36 reported (Org. Lett. 2010, 12, 5756. DOI: 10.1021/ol1026602) by Takaaki Sato and Noritaka Chida of Keio University.

D. F. Taber, Org. Chem. Highlights 2011, July 25.