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Oxidative Rearrangements of Tricyclic Vinylcyclobutane Derivatives
Author(s) -
Grota Juliane,
Mattay Jochen,
Piech Krzysztof,
Bally Thomas
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200501338
Subject(s) - chemistry , tricyclic , cyclopentene , methylene , photochemistry , quantum yield , ring (chemistry) , electron transfer , yield (engineering) , derivative (finance) , radical ion , medicinal chemistry , stereochemistry , ion , organic chemistry , fluorescence , physics , materials science , quantum mechanics , economics , financial economics , metallurgy , catalysis
Three tricyclic vinylcyclobutanes (3‐methylenetricyclo[5.3.0.0 2,6 ]decanes 1 – 3 ) have been subjected to ionization by photoinduced electron transfer in solution and by X‐irradiation in Ar matrices. All three compounds undergo oxidative cycloreversion; the cleavage of the four‐membered ring, however, occurs in a different direction depending on the presence of a methyl group in position 6 of the tricyclic framework. In those derivatives, cycloreversion is found to lead to 1‐methyl‐8‐methylene‐1,6‐cyclodecadiene radical cations ( 5 . + from 1 , 8 . + from 2 ) which upon back electron transfer yield two different hydrocarbons ( 6 from 5 . + , 9 from 8 . + ), depending on the configuration around the endocyclic double bonds of the respective cyclodecadiene derivative. In the absence of a methyl group on C6, the cycloreversion leads to a radical cation complex between 1‐methylenecyclopent‐2‐ene and cyclopentene ( 12 . + ) which appears to revert to 3 on back electron transfer. The intermediate radical cations 5 . + , 8 . + , and 12 . + have been identified and characterized by UV/Vis and IR spectra in Ar matrices. The mechanism of their formation is elucidated by quantum chemical calculations.