88557-55-5Relevant academic research and scientific papers
Total synthesis of (-)-ircinianin and (+)-wistarin
Uenishi, Jun'ichi,Kawahama, Reiko,Yonemitsu, Osamu
, p. 1691 - 1701 (1997)
(-)-Ircinianin (1), a cyclic furanosesterterpenetetronic acid isolated from a marine sponge (genus Ircinia), is synthesized in 17 steps from (S)-2-methylpropane-1,3-diol mono THP ether 10 and 3-furfural. The key step involves a NiCl2-CrCl2-mediated coupling reaction of iodotriene 9 with chiral aldehyde 8 in DMSO and subsequent intramolecular Diels-Alder reaction in one pot. Both reactions proceed very smoothly at room temperature and eventually give the cyclic product 30A possessing the desired cyclic skeleton of 1 in 60% yield. The structure of 30A is determined by X-ray crystallographic analysis. The stereochemistry of Diels-Alder reactions of 7A and another acyclic precursor 7B are discussed. The first total synthesis of (+)-wistarin (2) is accomplished in 55% yield by iodoether ring formation of 1 and hydrogenolysis of the iodide 33A. Based on the coupling constant in the proton NMR spectrum of 33A, the reported structure 2A is revised to 2B.
REVISION OF THE ABSOLUTE CONFIGURATION OF A-FACTOR; THE INDUCER OF STREPTOMYCIN BIOSYNTHESIS, BASING ON THE RECONFIRMED (R)-CONFIGURATION OF (+)-PARACONIC ACID
Mori, Kenji
, p. 3107 - 3109 (2007/10/02)
(+)-Paraconic acid was shown to be of (R)-configuration by its four-step conversion to (R)-(+)-3-methyl-4-butanolide.The absolute configuration at C-3 of A-factor was therefore revised to be R, since it was synthesized from (S)-(-)-paraconic acid.
