Premium
Vinyl‐to‐Benzyl Isomerization and Electrocyclizations in Lithio Derivatives of o ‐Tolylstilbenes
Author(s) -
Knorr Rudolf,
Lattke Ernst,
Ruf Friedrich,
Reißig HansUlrich
Publication year - 1981
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19811140503
Subject(s) - chemistry , isomerization , ring (chemistry) , medicinal chemistry , coalescence (physics) , ion , stereochemistry , organic chemistry , catalysis , physics , astrobiology
( Z) ‐2‐(2‐Methylphenyl)‐1,2‐diphenylvinyllithium (1) isomerizes in THF solution to give 1‐[2‐(lithiomethyl)phenyl]‐1,2‐diphenylethene (2) . Although 2 cannot be observed directly in this case, its intermediacy becomes evident from the independent preparation by metallation of 1‐[2‐(ethoxymethyl)phenyl]‐ (5) and 1‐(2‐methylphenyl)‐1,2‐diphenylethene (7) , with formation of the same sequential products from all three sources. 2 cyclizes by reversible attack on the syn ‐phenyl group to give a cyclohexadienide anion 3 containing a seven‐membered ring. 3 exhibits 1 H NMR coalescence phenomena and rearranges under thermodynamic control to the 1,2‐diphenyl‐1‐indanide anion 10 .