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The Photodecarbonylation of α‐Aryl Aldehydes: 1‐Formyl‐1‐methyl‐indan and heterocyclic analogues
Author(s) -
Wolf H.,
Gonzenbach H.U.,
Müller K.,
Schaffner K.
Publication year - 1972
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.19720550823
Subject(s) - chemistry , decarbonylation , aldehyde , heteroatom , disproportionation , aryl , singlet state , medicinal chemistry , stereochemistry , organic chemistry , excited state , catalysis , ring (chemistry) , physics , alkyl , nuclear physics
The singlet photodecarbonylation of the indanyl aldehyde 7 – a benzohomologue of laurolenal ( 1 ) and also a conformationally rigid ‘out‐of‐plane’ analogue of the α‐aryl aldehyde 4 previously studied [5] [6], – and of the heterocyclic derivatives 8 – 10 in degassed solutions, has been investigated. While 7 decarbonylates uniformly to the niethylindan 30 in close analogy to the examples studied previously, 8 and 9 decompose to the corresponding Δ 2 ‐unsaturated compounds 33 , 35 in addition to decarbonylation to 32 , 34 . The results provide an independent indication for intermediate photolytically formed radical pairs (a) in which heteroatoms facilitate radical removal of hydrogen from C(2), and thus introduce disproportionation to give unsaturated products + CH 2 O, competing with the otherwise exclusive alternative affording saturated products +CO.