The viability of nitrone-alkene (3 + 2) cycloadditions in alkaloid biosynthesis.
Although evidence has mounted in recent years for the biosynthetic relevance of [4 + 2] cycloaddition reactions, other cycloadditions have received much less attention. Herein we used density functional theory (DFT) calculations to assess the viability of nitrone-alkene (3 + 2) cycloaddition reactions proposed to occur during the biosynthesis of several alkaloid natural products (flueggines and virosaines). The results of our calculations indicate that these reactions have low enough intrinsic barriers and diastereoselectivity that they can proceed without enzymatic intervention.
Department of Chemistry, University of California, Davis , 1 Shields Avenue, Davis, California 95616, United States.
Phillip P
PP
Painter
Ryan P
RP
Pemberton
Bonnie M
BM
Wong
Krystina C
KC
Ho
Dean J
DJ
Tantillo
D000470:Alkaloids / Q000096:biosynthesis* / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D061565:Cycloaddition Reaction; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D011789:Quantum Theory; D013237:Stereoisomerism
D000470:Alkaloids; D000475:Alkenes; D001688:Biological Products; D009589:Nitrogen Oxides; C015388:nitrones