The stereocontrolled formation of cyclic vicinal cis-diols via a samarium diiodide pinacol coupling of dialdehydes
作者:Jose Luis Chiara、Walter Cabri、Stephen Hanessian
DOI:10.1016/s0040-4039(00)92024-0
日期:1991.2
Aliphatic 1,5- and 1,6 dialdehydes with and without α-substituents, as well as derivatives of carbohydrate dialdehydes undergo a pinacol coupling reaction in the presence of SmI2 to give cis-diols as the preponderant products. When α-alkoxy groups are present, the diol has an orientation that is opposite to such groups.
Carbohydrates to carbocycles: synthesis of the densely functionalized carbocyclic core of tetrodotoxin by radical cyclization of an anhydro sugar precursor
作者:Ricardo A. Alonso、Christopher S. Burgey、B. Venkateswara Rao、Gregory D. Vite、Roland Vollerthun、Mark A. Zottola、Bert Fraser-Reid
DOI:10.1021/ja00068a025
日期:1993.7
The core of tetrodotoxin is a densely functionalized carbocycle for which an annulated pyranose can be envisaged as a retron. The carbocyclic ring is constructed upon a rigid 1,6-anhydro template which permits the early introduction of the key angular nitrogen, and concomitantly positions a trap for reaction with a carbon-centered radical generated chemospecifically at C6. The carbocyclic entity is