Über die Coniferen‐Harzsäuren, 5. Abhandlung ¹ ): Nitrosochlorid, Nitrosit und Nitrosat der Pinabietinsäure und Abietinsäure (Levy ² )). Die Konstitution der Abietinsäure und des Abietins

Abstract

322.Ossian Aschan: mer die Coniferen-HarzsBuren, 5. Abhandlung I): Nitrosochlorfd, Nitrosit und Nitrosat der Pinabietinsaure und Abietinaiiure (Lev y 2)). Die Konstitution der AbietinsLure und des Abietins.[Aus dem Chem. Lalioratorium der Universitiit IIelsingfors.} (Eiugegangen am 17. Juli 1922.) Theorelisehes. Die Untersuchuog der HarzsHuren C~O E~O 0 2 geht his mf das J a h r 1824 zuriick, in welchem U n v e r d o r b e n seine d i l v i n s i u r e a und B P i n i n s L u r e a aus dem Harze von Nadelbaumen abschied. J edoch haben die zahlreichen Arbeiten w Lhrend der darauffolgenden hundert Jahre nicht viel Positives zur Kenntnis dieser Kijrper. besonders bezuglich der Trennung und Unterscheidung der eiozelnen HarzsLuren bezw. iiber den inneren Bau derselben gebracht, weil man dabei, bis auf wenige Ausnahmen, rnit nicht einheitlichem Material oder mit Gemischen verschiedener Harzsauren gearbeitet hat. Ausnahmen bilden eigentlich nur die Arbeiten V e s t e r b e r g s ' ) uber die beiden P i m a r s i u r e n , die sicher einheitlich sind').Auch die umfassende Untersuchung von M a c h 9, die sonst viel Interesse darbietet, wurde mit unreioem Material ausgefuhrt, da sie in der Aufstellung der Formel CI9Hss 02, die sicher unrichtig ist, gipfelte6). Erst L e v y ' )

Preparations ofC-Nitroso Compounds

“…Others have been prepared in the gaseous state using flow techniques, and the identification of the short-lived nitrosoethenes has been accomplished by microwave spectroscopy. [390][391][392][393][394] The bases used for dehydrohalogenation of the chlorooximes include triethylamine, 395 1,5-diaza-bicyclo[4,3,0]non-5-ene, 396 sodium alkoxides, 397 stirring a suspension of freshly ground sodium carbonate suspended in dry tert-butyl methyl ether 398 (or in diethyl ether 399 or methylene chloride 400 ), a two-phase system of aqueous sodium carbonate and methylene chloride, 401 stirring with sodium bicarbonate in alcohol, 402 and stirring with calcium hydroxide suspended in ethyl acetate containing 0.5% water. 403 For the synthesis of gaseous nitrosoalkenes, the chlorooxime is passed over sodium bicarbonate or potassium carbonate at room temperature, 392,394 although direct dehydrochlorination by pyrolysis at 450 °C is preferred.…”

“…The nitrosoalkenes formed may often be highly reactive and have only a transient existence at room temperature, but there are also some that are stable monomeric solids which have been fully characterized. Others have been prepared in the gaseous state using flow techniques, and the identification of the short-lived nitrosoethenes has been accomplished by microwave spectroscopy. − The bases used for dehydrohalogenation of the chlorooximes include triethylamine, 1,5-diaza-bicyclo[4,3,0]non-5-ene, sodium alkoxides, stirring a suspension of freshly ground sodium carbonate suspended in dry tert- butyl methyl ether (or in diethyl ether or methylene chloride), a two-phase system of aqueous sodium carbonate and methylene chloride, stirring with sodium bicarbonate in alcohol, and stirring with calcium hydroxide suspended in ethyl acetate containing 0.5% water . For the synthesis of gaseous nitrosoalkenes, the chlorooxime is passed over sodium bicarbonate or potassium carbonate at room temperature, , although direct dehydrochlorination by pyrolysis at 450 °C is preferred. − Dehydrochlorination of chlorooximes by triethylamine in organic solvents such as benzene, DMF, or acetonitrile results in rapid generation of nitrosoalkenes.…”

Nitrosyl Chloride.

“…2. Unsaturated cyclic hydrocarbons and derivatives (table 18) Compounds such as cyclopentadiene (422), dicyclopentadiene (287), and styrene (388) form crystalline adducts with nitrosyl chloride. Similarly a number of more complex materials, such as ß-bromostyrene, stilbene, 1,1-diphenylethylene, 1,4-dihydronaphthalene, p-ethoxy-^-methylstyrene, and 2,2,4,/3-tetramethylstyrene, form solid adducts (276,277,388).…”