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A New Access to Sterically Shielded Allenes
Author(s) -
Krause Norbert
Publication year - 1991
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.19911241139
Subject(s) - chemistry , steric effects , isomerization , ketone , medicinal chemistry , pyran , double bond , shielded cable , photochemistry , stereochemistry , organic chemistry , catalysis , electrical engineering , engineering
The synthesis of the sterically shielded allenes 2 and 5 by 1,6‐and 1,4‐addition of organocuprates to acceptor‐substituted enynes and diynes, respectively, is described. Treatment of the di‐ tert ‐butyl‐substituted allenes 2 with aqueous base does not cause double bond isomerization; whereas ester 2a is converted into the corresponding β‐allenic acid, ketone 2b yields the 2 H ‐pyran 6 .