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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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