A new route to trans-2,6-disubstituted piperidine-related alkaloids using a novel C2-symmetric 2,6-diallylpiperidine carboxylic acid methyl ester.
A novel C2-symmetric 2,6-diallylpiperidine carboxylic acid methyl ester 1 was prepared by the double asymmetric allylboration of glutaldehyde followed by an aminocyclization and carbamation. On the basis of desymmetrization of 1 using iodocarbamation, one allyl group of 1 was protected and monofunctionalizations of the resulting oxazolidinone 11 were performed. The reaction of the N-methoxycarbonyl piperidine 25 employing decarbamation reagent (n-PrSLi or TMSI) as a key step gave oxazolidinone 26 or 17 including an intramolecular ring formation, which was transformed in a few steps into (-)-porantheridine (2) and (-)-2-epi-porantheridine (3), respectively. In addition, the expedient synthesis of (+)-epi-dihydropinidine (4), (2R,6R)-trans-solenopsin A (5), and precoccinelline (6), starting from 11 is described.
Takahata
Hiroki
H
Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, Sendai, 981-8558, Japan. Takahata@tohoku-pharm.ac.jp
Saito
Yukako
Y
Ichinose
Motohiro
M
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D004952:Esters / Q000737:chemistry*; D015394:Molecular Structure; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry
C469608:2,6-diallylpiperidine carboxylic acid methyl ester; D000470:Alkaloids; D004952:Esters; D010880:Piperidines