A New Method for Acyclic Stereocontrol by Means of Chiral Bisallylic Diols
A New Method for Acyclic Stereocontrol by Means of Chiral Bisallylic Diols
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手性双烯丙基二醇非环立体控制的新方法
DOI：
10.1002/chin.199247310
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
S. Saito*
中科院分区：
文献类型：
--
作者：
S. Saito*
基于烯丙基类化合物的基态分子设计，以邻位（S，S）-或（R，R）-二醇单元为控制单元，建立了一种区分烯丙基类碳-碳双键非对映体的方法。受保护的邻位二醇基团，如果它们是最大的取代基，则应彼此相对排列，并且例如涉及烯丙基碳-碳双键的其余中等大小的基团相应地保持偏左。这种情况只允许一对暴露在外的非对映体受到外部试剂的攻击，因为剩余的一对非对映体相互屏蔽而不受分子间过程的影响。这种非对映体的选择性反应已被成功地应用于双Michael反应、四氧化锇催化的邻位羟基化反应、卤代醚化反应和Diels-Alder反应等非对映体选择性反应中，在各种情况下都产生了极高的非对映体过量，在选择性有机合成中具有广泛的应用前景。
A method for differentiating allylic diastereofaces of carbon-carbon double bonds has been developed based on the ground state molecular design of allylic compounds in which a protected vicinal (S, S) - or (R, R) -diol unit is incorporated as a controller. The protected vicinal diol groups, if they are the most bulky substituents, should arrange anti to each other and the remaining medium-sized groups involving the allylic carbon-carbon double bonds, for instance, stay gauche accordingly. This situation allows only a pair of diastereofaces exposed outside to be attacked by external reagents because a remaining pair of diastereofaces is mutually shielded from intermolecular processes. Such diastereo-bias has been successfully and diversely employed in diastereoselective processes such as double Michael reaction, osmium tetraoxide-catalyzed vicinal hydroxylation, halo-etherification, and Diels-Alder reaction, giving rise to exceptionally high diastereomeric excess for every case examined, appealing prospect for wide applicability in selective organic syntheses.