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First Synthesis of Medium‐Sized Ring Allenyl Lactams
Author(s) -
Perscheid Moritz,
Schollmeyer Dieter,
Nubbemeyer Udo
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201100830
Subject(s) - allene , chemistry , ketene , ring (chemistry) , claisen rearrangement , olefin fiber , stereochemistry , medicinal chemistry , organic chemistry , catalysis
Medium‐sized lactams bearing an axially chiral allene unit have been synthesized by using an aza‐ketene Claisen rearrangement. Starting from 2‐alkynylpiperidines or 2‐alkynylazepines, ring enlargement enabled the highly diastereoselective formation of 10‐ or 11‐membered lactams with a 4,5‐allene subunit. X‐ray analysis of the allenylacezinone showed the presence of a strained cumulated olefin system with a defined arrangement of the functional groups. The cyclic allenes were found to be stable upon heating up to 50 °C.