Synthesis of Functionalized Pyrans by Domino Metathesis Reaction of Oxabicyclo Derivatives: Dramatic Effect of Remote Substituents on Reactivity and Selectivity
Studies Directed Towards the Total Synthesis of (-)-Dictyostatin
作者:Jhillu S. Yadav、Vemula Rajender
DOI:10.1002/ejoc.200901448
日期:2010.4
The stereoselective synthesis of the three major fragments (C1-C9, C10-C17, and C19-C26) of an antimitotic marinemacrolide, (-)-dictyostatin, has been achieved with a desymmetrization strategy and Oppolzer syn and anti aldol protocols as the key reactions. Takai olefination and Sonogashira coupling reactions were successfully utilized to establish the 2Z,4E-dienoate portion of the C1-C9 fragment and
features of the synthesis are the formation of the Z-configured trisubstituted double bond by a one-pot esterification of allyl(diisopropoxy)borane and ring-closing metathesis, formation of the β-keto ester via ethyldiazoacetate addition to an aldehyde, and use of the Duthaler-Hafner acetate aldol reaction for the introduction of the stereocenter at C3. The practicality of this synthesis is demonstrated
作者:Kohei Tamao、Toshihiko Tohma、Naoki Inui、Osamu Nakayama、Yoshihiko Ito
DOI:10.1016/s0040-4039(00)88558-5
日期:1990.1
Catalyticasymmetricintramolecularhydrosilation of di(2-propenyl)methanol in the presence of a Rh(I) complex containing (R,R)-DIOP or (R)-BINAP as ligand, followed by hydrogen peroxide oxidation, afforded optically active (2S,3R)-2,4-dimethyl-4-penume-1,3-diol of up to 93% ee.