Concise synthesis of calystegines B<sub>2</sub> and B<sub>3</sub>via intramolecular Nozaki–Hiyama–Kishi reaction
作者:Hong-Yao Wang、Atsushi Kato、Kyoko Kinami、Yi-Xian Li、George W. J. Fleet、Chu-Yi Yu
DOI:10.1039/c6ob00697c
日期:——
The key step in the concise syntheses of calystegine B2 and its C-2 epimer calystegine B3 was the construction of cycloheptanone 8via an intramolecular Nozaki–Hiyama–Kishi (NHK) reaction of 9, an aldehyde containing a Z-vinyl iodide. Vinyl iodide 9 was obtained by the Stork olefination of aldehyde 10, derived from carbohydrate starting materials. Calystegines B2 (3) and B3 (4) were synthesized from
简洁地合成calystegine B 2及其C-2差向异构体calystegine B 3的关键步骤是通过分子内的Nozaki-Hiyama-Kishi(NHK)反应9(一种含有Z-乙烯基碘的醛)来构建环庚酮8。乙烯基碘化物9是通过醛10的斯托克烯化反应获得的,醛10是从碳水化合物原料中衍生出来的。由D-木糖和L合成Calystegines B 2(3)和B 3(4)。-阿拉伯糖衍生物分别经过11个步骤,具有优异的总收率(27%和19%)。
Short syntheses of enantiopure calystegine B2, B3, and B4
作者:Philip R. Skaanderup、Robert Madsen
DOI:10.1039/b102353p
日期:——
Calystegine B2, B3, and B4 have been prepared in 5 steps from the benzyl protected methyl 6-iodoglycopyranosides of glucose, galactose and mannose, respectively, by using a zinc-mediated domino reaction followed by ring-closing olefin metathesis as the key steps.
A Short Synthetic Route to the Calystegine Alkaloids
作者:Philip R. Skaanderup、Robert Madsen
DOI:10.1021/jo020645c
日期:2003.3.1
An efficient strategy is described for the synthesis of enantiopure calystegine alkaloids. The key step employs a zinc-mediated fragmentation of benzyl-protected methyl 6-iodo-glycosides followed by in situ formation of the benzyl imine and Barbier-type allylation with zinc, magnesium, or indium metal. Stereochemistry in the pivotal allylation is controlled by the choice of the metal. The functionalized