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.