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An Efficient Route to 4/5/6 Polycyclic β‐Lactams
Author(s) -
Desroy Nicolas,
RobertPeillard Fabien,
Toueg Julie,
Duboc Romain,
Hénaut Charlotte,
Rager MarieNoëlle,
Savignac Monique,
Genêt JeanPierre
Publication year - 2004
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.200400462
Subject(s) - chemistry , diene , cycloaddition , enyne metathesis , reactivity (psychology) , metathesis , bicyclic molecule , ether , salt metathesis reaction , nuclear magnetic resonance spectroscopy , diels–alder reaction , organic chemistry , combinatorial chemistry , medicinal chemistry , catalysis , medicine , natural rubber , polymer , alternative medicine , pathology , polymerization
The synthesis of 4/5/6 polycyclic β‐lactams by enyne metathesis and Diels−Alder reactions is described. Compared to the synthesis of 4/6/6 and 4/7/6 polycyclic β‐lactams previously reported by our laboratory, formation of the strained 4/5/6 compounds requires alternative reaction conditions. Indeed, the synthesis of the 4/5 bicyclic diene 12 was more difficult than those of the 4/6 ( 13 ) and 4/7 ( 14 ) dienes. The strain of the 4/5 system could be observed by NMR spectroscopy and molecular modelling. Moreover, the reactivity of 4/5 diene 12 towards Diels−Alder cycloaddition was also different from that of the 4/6 ( 13 ) and 4/7 ( 14 ) dienes. Cycloadditions with 4/5 diene 12 therefore had to be performed in lithium perchlorate/diethyl ether (LPDE) or in an ionic liquid in order to proceed in good yields with various dienophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)