A Complete Diastereo- and Enantioselective Synthesis of 1,2- and 1,3-Diols

利用恶唑硼烷酮促进的不对称Aldol反应，研究了1，2-和1，3-二醇的完全非对映和对映选择性合成。涉及手性中心的无环系统的立体选择性建设不受反应中使用的底物的立体化学。这是“催化剂控制”的一个新例子。重复该反应，我们可以得到一种新的构建完全受控的非对映异构体的策略。为了证实该策略的有效性，我们选择了HMG-CoA还原酶抑制剂的mevinic酸内酯衍生物，涉及顺式-1，3-二醇单元。我们的手性恶唑硼烷酮促进的4-苯基丁醛与甲硅烷基烯酮缩醛的羟醛缩合反应，其中含有二硫戊环，这允许生产相应的乙酸酯羟醛，具有几乎完全的对映选择性水平。由第一步反应得到的醛在相同的催化体系下进行第二步反应，得到预期的顺式-1，3-二醇。mevinic内酯衍生物非常容易合成。这是在催化剂控制下的对映选择性无环立体选择性的一个很好的例子。

A study on a complete diastereo- and enantioselective synthesis of 1,2- and 1,3-diols has been developed by using our oxazaborolidinone-promoted asymmetric aldol reaction. The stereoselective construction of acyclic systems involving chiral centers was not affected by the stereochemistry of the substrates used in the reaction. This is a novel example of "catalyst control". When such a reaction is repeated, we can get a new strategy of constructing complete controlled diastereoisomers. In order to confirm the effectiveness of the strategy, we chose a mevinic acid lactone derivative of HMG-CoA reductase inhibitors, involving a syn-1,3-diol unit. Our chiral oxazaborolidinone-promoted aldol reaction of 4-phenylbutanal with a silyl ketene acetal containing a dithiolane which allows the production of the corresponding acetate aldol with the level of almost complete enantioselectivity. The second aldol reaction of the aldehyde derived from the first aldol gave the expected syn-1,3-diol by the same catalytic system. The mevinic lactone derivative was very easily synthesized. This is an excellent example of enantioselective acyclic stereoselection under catalyst control.