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Die Gasphasen‐Flussthermolyse von 1‐Isobutenyl‐ und 2‐Methylphenyl‐alkinyl‐ketonen. Eine Synthese von Methylenomycin B
Author(s) -
Koller Manuel,
Karpf Martin,
Dreiding André S.
Publication year - 1986
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.19860690306
Subject(s) - chemistry , carbene , thermal decomposition , allylic rearrangement , intramolecular force , medicinal chemistry , yield (engineering) , triple bond , double bond , stereochemistry , organic chemistry , catalysis , materials science , metallurgy
The Gas‐Flow Thermolysis of 1‐Isobutenyl Alkynyl and 2‐Methylphenyl Alkynyl Ketones. Synthesis of Methylenomycin B The gas‐flow thermolysis of 1‐isobutenyl alkynyl or 2‐methylphenyl alkynyl ketones were found to lead to phenols and cyclopentenones or to naphthols and indanones, respectively. These conversions involve two cyclization processes so far unknown with α‐alkynones; they are interpreted as intramolecular additions of an allylic or a benzylic C,H bond to a triple bond which may occur in two directions. In addition, the cyclopentenones formed by the α‐alkynone cyclization, a known carbene process yielding 5‐rings, were also found. The available evidence ruled out a carbene process yielding 6‐rings. The addition process yielding 5‐rings was applied to a short (but low yield) synthesis of methylenomycin B .