3400-89-3Relevant academic research and scientific papers
Novel Products in the Weiss Reaction of 1,2-Cyclopentanedione. Improved Preparation of Propellane-3,7-dione
Quast, Helmut,Roeschert, Horst,Peters, Eva-Maria,Peters, Karl,Schnering, Hans Georg von
, p. 523 - 532 (2007/10/02)
The reaction of 1,2-cyclopentanedione (1c,9) with the 3-oxoglutarate 4 in methanol/water in the presence of sodium bicarbonate followed by hydrolysis and decarboxylation of the product mixture affords the oxapropellane ester 11c in addition to the propellanedione 6c.The alkali enolates of 4 react with 9 in boiling methanol to yield the yellow, poorly soluble alkali dihydropentalenolates 12M and the propellane tetraester 5c, which on hydrolysis and decarboxylation yields 53percent of 6c.The dihydropentalenol 12H equilibrates with the tautomeric β-oxodiester 13, the proportion of which increases with solvent polarity.In methanol solutions, 12H and 13 add diastereoselctively forming the dicyclopenta-s-indacene tetraester syn-14, which is derived from a novel pentacyclic ring system.The configuration of syn-14 is determined by X-ray diffraction analysis.The mechanisms of formation are discussed for 11c, 12M, and syn-14. - Keywords: Dicyclopenta-2-indacene/ 2-Oxapropellane derivatives/ Pentalene derivatives/ Propellane-3,7-dione/ Weiss reaction
