Intramolecular 1,3-dipolar cycloaddition-mediated stereoselective synthesis of disubstituted cyclopentane: a simple model for the cyclopentane ring system of polycyclic oroidine alkaloids.
We present a diastereoselective synthesis of disubstituted cyclopentane 8 having a nitrogen-containing quaternary carbon center, which is found in axinellamine A (5) and related compounds. During this work, we found that the 1,3-dipolar cycloaddition product 24 immediately underwent intramolecular redox reaction at the newly formed morpholin-2-one moiety, thus affording disubstituted cyclopentane containing a tertiary amine (9) stereoselectively in good yield. The amine 9 was successfully converted into guanidine 31, which corresponds to 8, through iminium cation-enamine isomerization.
Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
Yusuke
Y
Fukahori
Yohei
Y
Takayama
Takuya
T
Imaoka
Osamu
O
Iwamoto
Kazuo
K
Nagasawa
D000470:Alkaloids / Q000737:chemistry*; D061565:Cycloaddition Reaction; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011083:Polycyclic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D000470:Alkaloids; D003517:Cyclopentanes; D011083:Polycyclic Compounds