Premium
Gasphasen‐Thermolyse Methyl‐substituierter Bicyclo[3.2.0]hept‐2‐en‐7‐one
Author(s) -
Schiess Peter,
Fünfschilling Peter
Publication year - 1976
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19760590533
Subject(s) - chemistry , bicyclic molecule , thermal decomposition , methyl group , medicinal chemistry , conjugated system , sigmatropic reaction , pyrolysis , cyclopentadiene , decomposition , stereochemistry , group (periodic table) , organic chemistry , polymer , catalysis
Gas phase thermolysis of methyl‐bicyclo [3.2.0] hept‐2‐en‐7‐ones. Irradiation of methylnorbornenones 5a , 5b , 5c and 5e leads to the methyl‐bicyclo‐[3.2.0]hept‐2‐en‐7‐ones 4a , 4b , 4c and 4e , respectively. Upon flash thermolysis of these βγ‐unsaturated ketones dihydrotolualdehydes 9 and 10 and tolualdehydes 11 are formed as major products. The formation of these aldehydes is rationalized as involving methyl substituted ketenes 6 and conjugated heptatrienaldehydes 7 as intermediates. From the position of the methyl group in the stable pyrolysis products 9 , 10 and 11 the occurrence of a thermally induced [1, 5]‐sigmatropic shift of the formyl group in 1,2‐dihydro‐tolualdehyde 8 is inferred.