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Rh(I)‐katalysierte Umlagerungen von 3,4‐Diacycloxy‐1,5‐hexadiinen; synthese von ( E )‐4‐acyloxymethyliden‐2‐cyclopenten‐1‐onen
Author(s) -
Pürro Serge,
Pryde Andrew,
Zsindely Janos,
Schmid Hans
Publication year - 1978
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.19780610124
Subject(s) - chemistry , chloroform , catalysis , medicinal chemistry , stereochemistry , organic chemistry
Rh(I)‐Catalysed Rearrangements of 3,4‐Diacyloxy‐1,5‐hexadiynes; Synthesis of (E)‐4‐Acyloxymethyliden‐2‐cyclopenten‐1‐ones The 3,4‐diacyloxy‐1,5‐hexadiynes 3, 6 and 8 which were synthesized according to a known, slightly modified procedure react with [Rh(CO) 2 Cl] 2 at 100° in chloroform with formation of the ( E )‐4‐acyloxymethyliden‐2‐cyclopenten‐1‐ones 4, 7 and 9 ( Schemes 2, 3 and 4 ), respectively. DL ‐ and meso ‐ 3 as well as trans ‐ and cis ‐ 8 , give the same ( E )‐isomers 4 and 9 , respectively. 3,4‐Diacetoxy‐3, 4‐dimethyl‐1, 6‐diphenyl‐1,5‐hexadiyne ( 10 ) produces with the same catalyst 2,6‐diacetoxy‐3, 4‐dimethyl‐1,6‐diphenylfulvene ( 11 ) (Scheme 5) . A mechanism for the formation of the cyclopentenones is proposed in Scheme 6 .