Structure of alkaloid 275A, a novel 1-azabicyclo[5.3.0]decane from a dendrobatid frog, Dendrobates lehmanni: synthesis of the tetrahydrodiastereomers.
The principal alkaloid 275A in skins of the Colombian poison frog Dendrobates lehmanni has been identified as the pyrrolo[1,2-a]azepane (1), the first occurrence in nature of this "izidine" system. Tetrahydro-1 proved identical to one of the four synthetic diastereomers, 2a--2d, thereby establishing that 1 has the 5Z,10E relative stereochemistry. Alkaloid 1 is often accompanied by other congeners, in particular a 5Z,10Z diastereomer 15, a dihydro analogue 16, and a ketone 17. Such izidines in frogs may arise from dietary ants, as do other classes of izidines.
Garraffo
H M
HM
Laboratory of Bioorganic Chemistry, NIDDK, NIH, Bethesda, Maryland 20892-0820, USA. garraffo@helix.nih.gov
Jain
P
P
Spande
T F
TF
Daly
J W
JW
Jones
T H
TH
Smith
L J
LJ
Zottig
V E
VE
D000470:Alkaloids / Q000138:chemical synthesis / Q000737:chemistry*; D000818:Animals; D001001:Anura; D001372:Aza Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D002849:Chromatography, Gas; D015394:Molecular Structure; D013057:Spectrum Analysis; D013237:Stereoisomerism
C430147:1-azabicyclo(5.3.0)decane; D000470:Alkaloids; D001372:Aza Compounds; D001643:Bridged Bicyclo Compounds