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Photocycloaddition of Isocoumarins and Isothiocoumarins to Alkenes
Author(s) -
Kinder Michael A.,
Meyer Lars,
Margaretha Paul
Publication year - 2001
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 - 10.1002/1522-2675(20010815)84:8<2373::aid-hlca2373>3.0.co;2-4
Subject(s) - chemistry , isocoumarins , enone , irradiation , medicinal chemistry , organic chemistry , catalysis , nuclear physics , physics
On irradiation in the presence of tetrachloroethene (TCE), both isocoumarins 3 and isothiocoumarins 4 afford in high yields the cis ‐fused cycloadducts 8 and 9 , while only the oxacycles 3 undergo photocycloaddition to 2,3‐dimethylbut‐2‐ene (TME) to give mixtures of cis ‐ and trans ‐fused products 10 and 11 , respectively, in moderate yields. This higher efficiency in reacting with TCE as compared to TME for compounds 3 and 4 contrasts the behavior of simple cyclic enones, e.g. , 5,5‐dimethylcyclohex‐2‐enone ( 12 ), which is converted to bicyclooctanones about fifty times faster with TME than with TCE.