A new route to trans-2,6-disubstituted piperidine-related alkaloids using a novel C2-symmetric 2,6-diallylpiperidine carboxylic acid methyl ester
作者:Hiroki Takahata、Yukako Saito、Motohiro Ichinose
DOI:10.1039/b601489e
日期:——
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
通过戊二醛的双不对称烯丙基硼化,然后进行氨基环化和氨基甲酸酯化反应,制备了新型的C2对称的2,6-二烯丙基哌啶羧酸甲酯1。在使用碘代氨基甲酸酯化1的脱对称性的基础上,保护1的一个烯丙基,并对所得的恶唑烷酮11进行单官能化。N-甲氧基羰基哌啶25的反应采用脱氨基化试剂(n-PrSLi或TMSI)作为关键步骤,得到恶唑烷二酮26或17,包括分子内环的形成,在几步中将其转化为(-)-哌啶(2)和(-)-2-表-哌啶(3)。另外,描述了从11开始的(+)-表-二氢吡啶(4),(2R,6R)-反式-肾上腺素A(5)和前古西林碱(6)的方便的合成。