Photodehydrocyclizations of stilbene-like compounds VIII: Synthesis of hexaheliceno[3,4-c]hexahelicene
The synthesis of a new double helicene, hexaheliceno[3,4-c]hexahelicene, has been described. Of two possible diastereomers only one has been obtained. Presumably the product has the racemic configuration but this assignment is not yet definite.
Unsaturated Macrocyclic compounds—LII : The synthesis of 1,8-diethynylinaphthalene and its oxidation to a conjugated fourteen-membered ring system☆
Abstract A seven step synthesis of 1,8-diethynylnaphthalene (IX) from naphthalic anhydride (I) is described. Oxidation of IX with oxygen, cuprous chloride and ammonium chloride gave the very unstable “cyclic dimer” (XX), containing a conjugated 14-membered ring.
Über die Chlormethylierung des Naphthalins, III. 1-Methyl-4-halogenmethyl- und 1.4-Bis-brommethyl-naphthalin
1-Methyl-naphthalin gibt durch Halogenmethylierung 1-Methyl-4-brom-methyl- bzw.1-Methyl-4-jodmethyl-naphthalin, die analoge Fluormethylierung ergibt ein amorphes Produkt. 1-Methyl-4-chlormethyl-naphthalin wird der Hydrolyse, der Reduktion, der Umsetzung mit Kaliumcyanid und der Sommelet-Reaktion unterworfen. Die Bis-brommethylierung von Naphthalin liefert das 1.4-Derivat; aus 1.4-Bis-chlormethyl-naphthalin ist Naphthalin-dialdehyd-(1.4) erhalten worden.