A Stereoselective Approach to Functionalized Cyclohexenones
作者:Anne C. Meister、Paul F. Sauter、Stefan Bräse
DOI:10.1002/ejoc.201300752
日期:2013.11
A catalytic enantioselective approach to 4-hydroxy-6-methylcyclohex-2-enones is presented herein. The stereogenic information is generated through a copper-catalyzed 1,4-addition to p-benzoquinone monoketal using a chiral, BINOL-based (BINOL = 1,1′-bi-2-naphthol) phosphane ligand, according to the procedure of Feringa et al. A CBS (Corey–Bakshi–Shibata) reduction of the 1,4-adducts gave the four possible
Seven structurally related new polyoxygenated methyl cyclohexanoids, ampelomins A-G (1-7), were isolated from the mycelial solid culture of a soil-derived Ampelornyces fungus. Their structures were determined by spectroscopic and chemical means. Ampelomins A (1), C (3), E (5), and G (7) exhibited weak activity against a-glucosidase with IC50 values of 1.74-5.93 mM, and ampelomin A (1) showed moderate antibacterial activity with MIC90 values ranging from 202.4 to 1015.9 mu M. A plausible polyketide biogenetic pathway is postulated for these compounds.