Structure and Absolute Stereochemistry of the Anticancer Agent EBC-23 from the Australian Rainforest
作者:Lin Dong、Victoria A. Gordon、Rebecca L. Grange、Jenny Johns、Peter G. Parsons、Achim Porzelle、Paul Reddell、Heiko Schill、Craig M. Williams
DOI:10.1021/ja807133p
日期:2008.11.19
EBC-23 (2), a prostate anticanceragent, was isolated from the fruit of Cinnamomum laubatii (family Lauraceae) in the Australiantropicalrainforest. Extensive NOE experiments enabled the relative stereochemistry of the proposed EBC-23 (2) structure to be determined. Total synthesis of both enantiopodes over nine linear steps, involving challenging RCM and spiroacetal cyclizations, confirmed the gross
New optically active 8-hydroxy-3-alk(en)yl-3,4-dihydroisocoumarins 2a–c were isolated from Ginkgo biloba L. fruits. The absolute configuration was determined to be R by comparison with both enantiomers of the 8-hydroxy-3-tridecyl-3,4-dihydroisocoumarin synthesized from optically active epichlorhydrins.
Anticancer Agents from the Australian Tropical Rainforest: Spiroacetals EBC-23, 24, 25, 72, 73, 75 and 76
作者:Lin Dong、Heiko Schill、Rebecca L. Grange、Achim Porzelle、Jenny P. Johns、Peter G. Parsons、Victoria A. Gordon、Paul W. Reddell、Craig M. Williams
DOI:10.1002/chem.200901525
日期:2009.10.26
EBC‐23, 24, 25, 72, 73, 75 and 76 were isolated from the fruit of Cinnamomum laubatii (family Lauraceae) in the Australiantropicalrainforests. EBC‐23 (1) was synthesized stereoselectively, in nine linear steps in 8 % overall yield, to confirm the reported relative stereochemistry and determine the absolute stereochemistry. Key to the total synthesis was a series of Tietze–Smith linchpin reactions
Reduction of β-hydroxysulfoxides: Application to the synthesis of optically active epoxides
作者:Guy Solladié、Gilles Demailly、Christine Greck
DOI:10.1016/s0040-4039(00)61904-4
日期:1985.1
β-hydroxysulfoxides of opposite stereochemistry can be prepared in very high diastereoisomeric excesses (90 to 95%) by reduction of β-ketosulfoxides with DIBAL or DIBAL/ZnCl2. A very efficient method to transform these reduction products into opticallyactive epoxides is also described.