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Dienol‐Benzol‐Umlagerung von Penta‐2,4‐dienyl‐benzocyclohexadienolen
Author(s) -
Greuter Hans,
Hansen HansJürgen,
Schmid Hans
Publication year - 1973
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.19730560729
Subject(s) - chemistry , naphthalene , medicinal chemistry , ether , sigmatropic reaction , stereochemistry , organic chemistry
1‐Hydroxy‐2‐methyl‐2‐(penta‐2,4‐dienyl)‐1,2‐dihydronaphthalene ( 2 ), on treatment with 0,75N H 2 SO 4 in ether at 0°, underwent a [1 s , 2 s ]‐sigmatropic rearrangement to give 2‐methyl‐1‐(penta‐2,4‐dienyl)‐naphthalene ( 5 ), cf . scheme 2 . 2‐Hydroxy‐1‐methyl‐1‐(penta‐2,4‐dienyl)‐1,2‐dihydronaphthalene ( 4 ) under the same conditions gave 38% of the [1 s , 2 s ]‐product 1‐methyl‐2‐(penta‐2,4‐dienyl)‐naphthalene ( 6 ), together with 26% 1‐methylnaphthalene, 21% 1‐methyl‐4‐(penta‐2,4‐dienyl)‐naphthalene ( 7 ) and 1% 1‐methyl‐5‐(penta‐2,4‐dienyl)‐naphthalene ( 8 ), cf . scheme 2. Most likely the latter two naphthalene derivatives at least are products of an intermolecular process.