Further studies of the Daphniphyllum alkaloid polycyclization cascade.
The scope of the 2-azadiene intramolecular Diels-Alder cyclization, previously employed for synthesis of the Daphniphyllum alkaloids, has been further investigated. Through a series of 1,5-diol cyclization precursors the substitution pattern of both the dienophile and the 2-azadiene were examined. From these studies it was shown that the cascade reaction is tolerant toward a variety of alkyl-substituted dienophiles. However, it was also demonstrated that this reaction is very sensitive to the substitution pattern of the 2-azadiene. Alterations made to the structure of the 2-azadiene cause either competing side reactions or complete failure of the reaction cascade.
Wallace
G A
GA
Center for New Directions in Organic Synthesis, Department of Chemistry, University of California, Berkeley, California 94720, USA.
Heathcock
C H
CH
D000470:Alkaloids / Q000096:biosynthesis* / Q000138:chemical synthesis* / Q000737:chemistry; D032462:Cycadopsida / Q000378:metabolism*; D007202:Indicators and Reagents; D015394:Molecular Structure; D013329:Structure-Activity Relationship; D014197:Trees / Q000378:metabolism
D000470:Alkaloids; D007202:Indicators and Reagents