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The Thermal Transformations of Bicyclopropylidene and Methylenespiropentane Revisited
Author(s) -
Schill Heiko,
Kozhushkov Sergei I.,
Walsh Robin,
de Meijere Armin
Publication year - 2007
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200601100
Subject(s) - chemistry , isomerization , reaction rate constant , medicinal chemistry , stereochemistry , kinetics , organic chemistry , catalysis , physics , quantum mechanics
Abstract The overall and the individual rate constants of the unimolecular thermal isomerization of methylenespiropentane ( 4 ) to 1,2‐ and 1,3‐dimethylenecyclobutanes ( 7 and 8 ) have been determined to be lg ( k – 4 /s –1 ) = (13.78 ± 0.06) – (49.7 ± 0.2) kcal mol –1 / RT · ln 10, lg ( k 7 /s –1 ) = (13.03 ± 0.19) – (48.0 ± 0.6) kcal mol –1 / RT · ln 10 and lg ( k 8 /s –1 ) = (14.15 ± 0.19) – (52.4 ± 0.5) kcal mol –1 / RT · ln 10, respectively. The activation energies are significantly lower than that for the rearrangement of the parent spiropentane.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)