Synthesis of adamantanoid ketones from bridgehead alcohols by the hypoiodite thermolysis-cyclization sequence

Abstract

The reaction of 2,4,5-triphenyl-3H-pyrrol-3-one I-oxide with dimethyl acetylenedicarboxylate gave pyridine 9a, 4(3H)-pyridone loa, isoxazolidine 11, and traces of pyridone 13. Pyridone 10a is not an intermediate in the formation of 9a, yet on photolysis or pyrolysis above its melting point, loa yielded pyridine 9a. Possible reaction mechanisms that rationalize the formation of these products are discussed.

The Protoadamantane Radical Cation

“…Evaporation gave 220 mg of a mixture of 1/6-bromoadamantane/ 3-bromoadamantane in a ratio of 0.30:1.00:0.05 according to GC/ MS. 6-Protoadamantyl-and 3-protoadamantyl bromides were identified from standard samples prepared from 6-hydroxyprotoadamantane [50] and 3-hydroxyprotoadamantane, [51] respectively, by treatment with SOBr 2 in CCl 4 .…”

Adamantane-1,2-diol

“…Adamantane-1,2-diol was synthesized via a four-step synthesis according to the methods of McKervey et al (1971) and Janjatovic et al (1980). After repeated recrystallization from methanol at room temperature, colourless block-shaped crystals of (I) were obtained.…”

(±)-Adamantane-1,2-diyl diacetate

“…Adamantane-1,2-diacetate was prepared as described previously (McKervey et al, 1971;Janjatovic & Majerski, 1980) and was crystallized from a chloroform/2-propanol mixture as large colourless blocks, which were cut to provide suitable crystals for structural analysis.…”