Asymmetric Total Synthesis of (+)-Inthomycin C via O-Directed Free Radical Alkyne Hydrostannation with Ph3SnH and Catalytic Et3B: Reinstatement of the Zeeck-Taylor (3R)-Structure for (+)-Inthomycin C
Asymmetric Total Synthesis of (+)-Inthomycin C via O-Directed Free Radical Alkyne Hydrostannation with Ph3SnH and Catalytic Et3B: Reinstatement of the Zeeck-Taylor (3R)-Structure for (+)-Inthomycin C
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DOI：
10.1021/ol5000499
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发表时间：
2014-02-21
期刊：
影响因子：
5.2
通讯作者：
Maczka, Maciej
中科院分区：
文献类型：
--
作者：
Hale, Karl J.;Grabski, Milosz;Maczka, Maciej
据报道，一种 (+)-inthomycin C 的新途径利用 (-)-12 上的 O 导向自由基氢化锡化反应和 Stille 交叉偶联作为关键步骤。值得注意的是，后一个过程在 19 上发生，其中稀-戊烷排斥相互作用可能会干扰。我们对炔醇 (-)-12 和烯炔 (+)-7 的立体化学研究证实，Ryu 和 Hatakeyama 对 (+)-inthomycin C 的 (3S)-立体化学修改是无效的，而 Zeeck 和 Taylor 对 (+)-inthomycin C 的原始 (3R)-立体结构是正确的。
A new pathway to (+)-inthomycin C is reported that exploits an O-directed free radical hydrostannation reaction on (-)-12 and a Stille cross-coupling as key steps. Significantly, the latter process was effected on 19 where a gauche-pentane repulsive interaction could interfere. Our stereochemical studies on the alkynol (-)-12 and the enyne (+)-7 confirm that Ryu and Hatakeyama's (3S)-stereochemical revision of (+)-inthomycin C is invalid and that Zeeck and Taylor's original (3R)-stereostructure for (+)-inthomycin C is correct.