发现(1 R,2 S,3 R,4 S)-3-氨基-2-羟基冰片烷是合成高光学纯度的官能化杂螺旋体的有效手性助剂。2-(2-萘[2,1-b]噻吩亚乙烯基)苯并[1,2-b:4,3-b']二噻吩-5-羧酰胺的光环化反应得到非对映异构体混合物的螺旋烯,可通过柱色谱法轻松分离。从非对映异构体上除去手性助剂分别产生具有[α] D -2770°的2-甲氧基羰基-[7]杂庚烯和具有[α] D + 2830°的对映体。
发现(1 R,2 S,3 R,4 S)-3-氨基-2-羟基冰片烷是合成高光学纯度的官能化杂螺旋体的有效手性助剂。2-(2-萘[2,1-b]噻吩亚乙烯基)苯并[1,2-b:4,3-b']二噻吩-5-羧酰胺的光环化反应得到非对映异构体混合物的螺旋烯,可通过柱色谱法轻松分离。从非对映异构体上除去手性助剂分别产生具有[α] D -2770°的2-甲氧基羰基-[7]杂庚烯和具有[α] D + 2830°的对映体。
Diastereocontrolled synthesis of optically pure functionalized heterohelicenes
作者:Kazuhiko Tanaka、Hideji Osuga、Hitomi Suzuki
DOI:10.1016/s0957-4166(00)80425-5
日期:1993.8
preparation of functionalized opticallypureheterohelicenes. The diastereoselectivities in the synthesis of the helicenes via photocyclization were controlled by the use of these chiral auxiliaries and the resulting diastereomers were readily separated by column chromatography. Removal of the chiral auxiliaries gave opticallypure (+)-(P)- and (−)-(M)-[7]heterohelicenes, whose rotational values were
Practical Synthesis of Optically Pure Bifunctionalized Heterohelicenes
作者:Hideji Osuga、Hitomi Suzuki、Kazuhiko Tanaka
DOI:10.1246/bcsj.70.891
日期:1997.4
2-f]quinolines containing π-excessivethiophene and π-deficientpyridineunits were prepared by the use of exo-3-amino-2-hydroxybornane as a chiral auxiliary. This procedure consists of separation of the helical diastereomers prepared by photocyclization of 1,2-diarylethylenes and removal of the chiral auxiliary by a thiolate ion. Large scale preparation of the helicenes can be accomplished by a modified
Both enantiomers of new bifunctionalhelicenes constructed from π-excessive 2-(hydroxymethyl)thiophene and π-deficientpyridine rings have been prepared using (1R,2S,3R,4S)-3-amino-2-hydroxybornane as a chiral auxiliary. The X-ray crystalstructure reveals the intermolecular hydrogen bond between the hydroxy group of the helicene and the pyridine nitrogen atom of the adjacent molecule. The non-bonded