144141-25-3Relevant academic research and scientific papers
AN EFFICIENT SYNTHETIC METHOD FOR OPTICALLY PURE HETEROHELICENES
Tanaka, Kazuhiko,Osuga, Hideji,Suzuki, Hitomi,Kishida, Hiroshi
, p. 4599 - 4602 (1992)
(1R,2S,3R,4S)-3-amino-2-hydroxybornane was found to be an efficient chiral auxiliary in the synthesis of functionalized heterohelicenes of high optical purity.Photocyclization of 2-(2-naphthothienylvinylene)benzodithiophene-5-carboxamide afforded helicenes as a diastereomeric mixture which was readily separated by column chromatography.Removal of the chiral auxiliary from the diastereomers produced 2-methoxycarbonylheterohelicene with D -2770 deg and its enantiomer with D +2830 deg, respectively.
Diastereocontrolled Synthesis of Optically Pure Functionalized Heterohelicenes
Tanaka, Kazuhiko,Osuga, Hideji,Suzuki, Hitomi
, p. 1843 - 1856 (1993)
(1R,2S,3R,4S)-exo-3-Amino-exo-2-hydroxyborane (exo-amino alcohol) and (1R,2R,3S,4S)-endo-3-amino-endo-2-hydroxybornane (endo-amino alcohol) were found to be efficient diastereomeric chiral auxiliaries for the preparation of functionalized optically pure heterohelicenes.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 optically pure (+)-(P)- and (-)-(M)-heterohelicenes, whose rotational values were +2830 and -2770 respectively.
