secondary alkyl iodides bearing a remote alkynylsilane underwent intramolecularcarbolithiations triggered by an I/Li-exchange performed at −100 °C using t-BuLi (2.5 equiv). The resulting alkenyllithiums were stereoselectively converted to tetrasubstituted cyclopentane exo-alkylidenes. After Pd-catalyzed hydrogenation, cyclopentanes and cis-bicyclo[4.3.0]nonanes were obtained with stereocontrol of
A carbohydrate approach for the formal total synthesis of (−)-aspergillide C
作者:Pabbaraja Srihari、Namballa Hari Krishna、Ydhyam Sridhar、Ahmed Kamal
DOI:10.3762/bjoc.10.329
日期:——
An enantioselective formal totalsynthesis of aspergillide C is accomplished using commercially available tri-O-acetyl-D-galactal employing a Ferrier-type C-glycosylation, utilizing a Trost hydrosilylation and protodesilylation as key reactions.
Synthesis and biological evaluation of 12-, 13-, 14-membered macrolides and open chain 2,6-trans-disubstituted dihydropyran analogues for aspergillides
Stereoselective synthesis of twenty (three 12-, five 13- and twelve 14-membered) macrolides and seventeen functionalized 2,6-trans-disubstituted dihydropyran derivatives have been achieved. The key reactions include an Achmatowicz rearrangement, Ferrier-type alkynylation, Yamaguchi macrolactonization and Lindlar’s hydrogenation. Biological screening of the synthesised compounds showed moderate activity
Stereodivergent Total Synthesis of (+)-Aspergillide B and (+)-7-<i>epi</i>-Aspergillide A
作者:Y. Sridhar、P. Srihari
DOI:10.1002/ejoc.201201155
日期:2013.1
The stereoselective total syntheses of (+)-aspergillide B and (+)-7-epi-aspergillide A were achieved. The key reactions include Noyori's asymmetric transfer hydrogenation, an Achmatowicz rearrangement, a Ferrier-type alkynylation, a hydrosilylation–protodesilylation, a CBS (Corey–Bakshi–Shibata) oxazaborolidine reduction, a Yamaguchi macrolactonization, and a Mitsunobu macrolactonization.
Total Synthesis of Both Enantiomers of Macrocyclic Lactone Aspergillide C
作者:P. Srihari、Y. Sridhar
DOI:10.1002/ejoc.201100917
日期:2011.11
A facile approach to the totalsynthesis of both enantiomers of the 14-membered macrolactone aspergillide C is described. The strategy employed was also utilized for the synthesis of C4-epimers of both the enantiomers of aspergillide C. The key reactions include Sharpless kinetic resolution, Achmatowicz reaction, Ferrier type alkynylation, hydrosilylation-protodesilylation, Corey–Bakshi–Shibata (CBS)
描述了一种简单的方法来全合成 14 元大环内酯曲霉内酯 C 的两种对映异构体。所采用的策略也用于合成曲霉醇 C 对映异构体的 C4-差向异构体。 关键反应包括 Sharpless 动力学拆分、Achmatowicz 反应、Ferrier 型炔基化、氢化硅烷化-原脱甲硅烷化、Corey-Bakshi-Shibata (CBS) 介导的还原和山口大环内酯化。