57239-03-9Relevant academic research and scientific papers
Synthesis of bicyclic diones and thiones. Facile methylation of the enolates of bicycloheptane-2,5-dione and bicyclooctane-2,5-dione. An AM1 computational study of bicyclic enolates
Werstiuk, N. H.,Yeroushalmi, S.,Guan-Lin, Hong
, p. 974 - 980 (2007/10/02)
A group of bicyclic ketones and thiones have been synthesized for homenolization studies.Bicycloheptane-2,5-dione (6) undergoes unusually rapid tetramethylation giving 3,3,6,6-tetramethylbicycloheptane-2,5-dione (1) in good yield.Treatment of 1 with P2S5 in xylene gave 3,3,6,6-tetramethylbicycloheptane-2,5-dithione (2) and 3,3,6,6-tetramethyl-5-oxo-bicycloheptane-2-thione (3), which was converted into 4 with Raney nickel.Bicyclooctane-2,5-dione (7), prepared via Diels-Alder reaction between 2-trimethylsilyloxy-1,3-cyclohexadiene and α-acetoxyacrylonitrile followed by a one-step desilylation/hydrolysis, also undergoes facile tetramethylation giving 3,3,6,6-tetramethylbicyclooctane-2,5-dione (5) in good yields.AM1 calculations were carried out on the α-enolates of bicycloheptan-2-one, 6, 5-methylidenebicycloheptan-2-one, and 4-acetylbicycloheptan-2-one in an attempt to gain information on the source of the enhanced acidity of the C-3 hydrogens of 6 and 7. Key words: bicyclic ketones, thiones, synthesis.
