SYNTHESIS OF UNSATURATED AMINO-ACIDS BY [3,3]-SIGMATROPIC REARRANGEMENT OF CHELATE-BRIDGED GLYCINE ESTER ENOLATES
SYNTHESIS OF UNSATURATED AMINO-ACIDS BY [3,3]-SIGMATROPIC REARRANGEMENT OF CHELATE-BRIDGED GLYCINE ESTER ENOLATES
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DOI：
10.1002/anie.199409981
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发表时间：
1994-05-18
期刊：
影响因子：
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通讯作者：
KAZMAIER, U
中科院分区：
文献类型：
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作者：
KAZMAIER, U
金属烯烃加速重排的驱动力可能是高能的酯烯醇酸盐转变为螯合桥联的稳定的羧酸盐。如果巴豆酯1中的酸性酰胺质子被甲基取代。这种络合作用不会发生。没有观察到重排。对于N-邻苯二甲酰基保护的甘氨酸烯丙基酯也是如此。鉴于氯化锌得到了很好的结果，我们利用这个体系详细地研究了双键取代基、烯烃构型和N-保护基对重排的产率和非对映选择性的影响(方案11，由于方案11的选择性
The driving force for the accelerated rearrangement of the metal enolates is probably the transformation of the high-energy ester enolate into a chelate-bridged, stabilized carboxylate. If the acidic amide proton in crotyl ester 1 is replaced by a methyl group. this chelation does not occur. and no rearrangement is observed. The same applies for N-phthaloyl-protected glycine allyl esters.I n view of the good results obtained with zinc (") chloride, we used this system to carry out a detailed study into the influence of the substituents at the double bond. the olefin configuration, and the N-protective group on the yield and diastereoselectivity of the rearrangement (Scheme 11, since the selectivity for