e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Comprehensive synthetic route to eight diastereomeric Podophyllum lignans
…, D Rajapaksa, NJ Taylor, R Rodrigo
Index: Forsey, Steven P.; Rajapaksa, Dayananda; Taylor, Nicholas J.; Rodrigo, Russell Journal of Organic Chemistry, 1989 , vol. 54, # 18 p. 4280 - 4290
An oxabicyclo compound, 9, prepared in 47% yield through an isobenzofuran intermediate was converted with excellent regio-and stereocontrol to eight (i)-lignan lactones of the podophyllotoxin series. One of the eight, epiisopicropodophyllin, 36, the 1, 2, 3, 4-cis isomer, previously unknown, was prepared as its methyl ether, 37. A comparative study of the'H NMR spectra of all eight lactones aided by an X-ray crystal structure of a 2, 3-cis lactone, ...