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Attempts To Improve the Overall Stereoselectivity of the Ireland-Claisen Rearrangement
被引:28
作者:
Chen, Chi-Li
[1
]
Namba, Kosuke
[1
]
Kishi, Yoshito
[1
]
机构:
[1] Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA
基金:
美国国家卫生研究院;
关键词:
ANTITUMOR POLYETHER MACROLIDE;
SPONGE LISSODENDORYX SP;
HALICHONDRIN-B;
MARINE SPONGE;
NORHALICHONDRIN-B;
D-GLUCOSE;
RING;
CONSTRUCTION;
INTERMEDIATE;
SEGMENT;
D O I:
10.1021/ol8027225
中图分类号:
O62 [有机化学];
学科分类号:
070303 ;
081704 ;
摘要:
With focus on the steric effects present in the transition states for the [3,3]-sigmatropic rearrangement, the substrate 5 has been designed to improve the overall stereoselectivity of the Ireland-Claisen rearrangement. Experimentally, it has been found that (1) only Z-6 rearranges to 7 at 80 degrees C and (2) E-6 isomerizes to Z-6 at 80 degrees C, thereby allowing the transformation of 5 into 7 in an almost quantitative yield. To illustrate the usefulness of this approach, two additional examples are given.
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页码:409 / 412
页数:4
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