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Approach to the Core Structure of Schweinfurthin B
Author(s) -
Roos Dominika,
Maier Martin E.
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202003749
Subject(s) - xanthene , chemistry , cyclohexanone , cycloaddition , ring (chemistry) , substituent , ketene , methylene , silylation , ether , lewis acids and bases , enol ether , medicinal chemistry , stereochemistry , photochemistry , organic chemistry , catalysis
We investigated approaches to the xanthene part of schweinfurthin B. Starting from an exo ‐methylene cyclohexanone, an organocuprate addition led to a cyclohexanone featuring a functionalized benzyl substituent in the 2‐position. Ring‐closing reactions to the tetrahydroxanthene core (formation of the central ring) were possible in moderate yield by attack of a phenolic oxygen function on the keto group. More effective was the cyclization to the xanthene core structure after conversion of the cyclohexanone to the exo ‐methylene cyclohexane derivative and Lewis acid mediated addition of the phenolic OH to the double bond. In addition, we tried to form the xanthene ring system in a model study by cycloaddition reaction of a silyl enol ether with an ortho ‐quinone methide.