Durch Aluminiumchlorid katalysierte Reaktionen. XII. Über eine Halogenwanderung in Kohlenstoffketten und Ringen

Studies in Dieckmann cyclization and utilization of the products in the synthesis of steroids

“…To prepare the afore mentioned hydroxy triester; we condensed 28 the sodio salt of ethyl methyl fl-ketoadipate (42) with ethyl bromoacetate to obtain ethyl methyl 2-carbethoxy-3-ketopimelate (43). The sodio salt of (43) was alkylated with methyl iodide to afford ethyl methyl 2-methyl-2-carbethoxy-3-ketopimelate (44). The sodium borohydride reduction of the keto triester (44), instead of giving the required hydroxy pimelic ester, furnished a mixture of the lactonic esters (45 and 46), which on cyclization by heating under reflux with potassium t-butoxide in t-butanol gave a mixture of a lactonic $-keto ester (47) and a fl-keto lactonic ester (48).…”

“…The sodio salt of (43) was alkylated with methyl iodide to afford ethyl methyl 2-methyl-2-carbethoxy-3-ketopimelate (44). The sodium borohydride reduction of the keto triester (44), instead of giving the required hydroxy pimelic ester, furnished a mixture of the lactonic esters (45 and 46), which on cyclization by heating under reflux with potassium t-butoxide in t-butanol gave a mixture of a lactonic $-keto ester (47) and a fl-keto lactonic ester (48). That a mixture was obtained in the above two steps was proved by the NMR spectrum of the cyclization product which showed the carbomethoxy group singlet and the triplet and quartet of the carbethoxy group present in (47) and (48) respectively.…”

Reaction of Aluminum and Carbon Tetrachloride, I

“…Several olefin-type compounds (cyclohexene and isoprene) in which no heterocyclic atom is present also were effective although to a lesser extent than the other retarders previously mentioned. There is a basis for selecting olefins since olefins formed by pyrolysis of paraffins in the presence of aluminum chloride polymerize and remain bound fast with the aluminum chloride according to Nenitzescu (13)(14)(15). The specificity of the olefinic linkage was demonstrated by showing that cyclohexane has no retardation effect.…”