Intermolecular and Intramolecular Diels−Alder Cycloadditions of 3-Ylidenepiperazine-2,5-diones and 5-Acyloxy-2(1H)-pyrazinones

The 3-ylidenepiperazine-2,5-diones 16 and 39 and 5-acyloxy-2(1H)-pyrazinones 17 can serve as starting materials for the Diels−Alder reactions of alkenes and alkynes to the piperazine ring, under acidic conditions or in the presence of acetyl chloride, to afford tricyclic piperazine-2,5-diones 19, 20...

Full description

Saved in:
Bibliographic Details
Published in:Journal of organic chemistry 2001-06, Vol.66 (11), p.3984-3997
Main Authors: Jin, Shangde, Wessig, Pablo, Liebscher, Jürgen
Format: Article
Language:English
Subjects:
Acylation
Cyclization
Fungi - chemistry
Indicators and Reagents
Molecular Conformation
Piperazines - chemistry
Pyrazines - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The 3-ylidenepiperazine-2,5-diones 16 and 39 and 5-acyloxy-2(1H)-pyrazinones 17 can serve as starting materials for the Diels−Alder reactions of alkenes and alkynes to the piperazine ring, under acidic conditions or in the presence of acetyl chloride, to afford tricyclic piperazine-2,5-diones 19, 20, 23−25, 27, 44, and 45. Intramolecular cycloadditions occur if 3-ylidenepiperazine-2,5-diones 30 and 32 are used as the starting materials. This procedure is a convenient path to bridged bicyclo[2.2.2]diazaoctane ring systems such as 31 and 33, the former being found in biologically active secondary mold metabolites, such as VM55599 (1) or brevianamide A (5), which have been isolated from various fungi. The synthesis of the indole compound 31 provided evidence for the proposed biochemical pathway with a Diels−Alder reaction as key step. Quantum chemical calculations have revealed that piperazinones with a cationic azadiene moiety are the most reactive species in Diels−Alder cycloadditions.
ISSN:0022-3263
1520-6904
DOI:10.1021/jo0100897