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@article{838539,
author = {Dreher, Spencer and Paruch, Kamil and Katz, Thomas},
article_number = {65},
keywords = {helicene; alkoxyl; diastereomer; separation},
language = {eng},
issn = {0022-3263},
journal = {Journal of Organic Chemistry},
title = {Acidified Alcohols as Agents to Introduce and Exchange Alkoxyls on the Periphery of Helicenes},
volume = {2000},
year = {2000}
}
TY - JOUR
ID - 838539
AU - Dreher, Spencer - Paruch, Kamil - Katz, Thomas
PY - 2000
TI - Acidified Alcohols as Agents to Introduce and Exchange Alkoxyls on the Periphery of Helicenes
JF - Journal of Organic Chemistry
VL - 2000
IS - 65
SP - 806-814
EP - 806-814
SN - 00223263
KW - helicene
KW - alkoxyl
KW - diastereomer
KW - separation
N2 - Alcs. contg. HCl transform the hydroquinone redn.-products of helicenebisquinones into p-alkoxyphenols that have the alkoxyls specifically on the peripheries of the helixes. The reactions are quick, and the yields are high. Alkoxyls at the 6-position are replaced also, but only after 2 h at 60 C, not after the 5 min at 25 C sufficient to replace the peripheral hydroxyls of the hydroquinones. After the remaining inside hydroxyls of a dihydroxytetramethoxy[6]helicene prepd. by this procedure were converted into camphanates, one diastereomer crystallizes from soln., allowing an enantiomer resoln. to be carried out on a large scale. By then simply re-applying the procedure with alc. acid, a variety of resolved dihydroxytetraalkoxy[6]helicenes can be prepd. in excellent yields without resoln. procedures having to be developed for each. Similar procedures are effective when applied to a [7]carbohelicene.
ER -
DREHER, Spencer, Kamil PARUCH a Thomas KATZ. Acidified Alcohols as Agents to Introduce and Exchange Alkoxyls on the Periphery of Helicenes. \textit{Journal of Organic Chemistry}. 2000, roč.~2000, č.~65, s.~806-814. ISSN~0022-3263.
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