NOVEL SPONGE-DERIVED AMINO-ACIDS .11. THE ENTIRE ABSOLUTE STEREOCHEMISTRY OF THE BENGAMIDES
NOVEL SPONGE-DERIVED AMINO-ACIDS .11. THE ENTIRE ABSOLUTE STEREOCHEMISTRY OF THE BENGAMIDES
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DOI：
10.1021/jo00288a039
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发表时间：
1990-01-05
影响因子：
3.6
通讯作者：
CREWS, P
中科院分区：
文献类型：
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作者：
ADAMCZESKI, M;QUINOA, E;CREWS, P
苯并酰胺A(1)和B(2)的完全立体化学可归属为5R、6S、7R、8R、10S、13S，这种绝对立体化学也可扩展到其他苯酰胺衍生物C、D、E和F(3-6)和异苯二胺E(7)。通过分离单羟基内酯12，然后将其转化为二羟基内酯11，得到了绝对的立体化学结果。11的相对立体化学已被证明与苯并酰胺类化合物中2-methoxy-3，4，5-trihydroxy-8-methylnon-6(E)-enoyl侧链(A)的相对立体化学相同。内酯12的绝对立体化学是通过与O-甲基扁桃酸的酯化，然后分析它们的不同1H核磁共振化学位移而得到的，给出了A中立体中心的绝对构型，结合新的指认和先前对苯酰胺的β-羟基己内酰胺部分得到的结果，完成了对所有手性中心的绝对构型的指认。
The complete stereochemistry of bengamides A (1) and B (2) can be assigned as 5R,6S,7R,8R,10S,13S, and this absolute stereochemistry can also be extended to other bengamide derivatives C, D, E, and F (3-6) and isobengamide E (7). The absolute stereochemical results were obtained by isolating a monohydroxy lactone 12, which was then converted to dihydroxy lactone 11. The relative stereochemistry of 11 had been previously shown to be the same as that of the 2-methoxy-3,4,5-trihydroxy-8-methylnon-6(E)-enoyl side chain (A) in the bengamides. The absolute stereochemistry of lactone 12, deduced by esterifying with O-methylmandelic acids followed by an analysis of their different 1H NMR chemical shifts, gave the absolute configuration of the stereocenters in A. Combining the new assignments with those obtained previously for the .delta.-hydroxycaprolactam moiety of the bengamides completed assignment of the absolute configuration at all chiral sites.