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醛醇反应，研究了1,2-和1,3-二醇的完全非映对和对映选择性合成。涉及手性中心的无环体系的立体选择结构不受反应中底物的立体化学性质的影响。这是“催化剂控制”的一个新例子。当这样的反应被重复时，我们可以得到一种构造完全受控非对映异构体的新策略。为了证实该策略的有效性，我们选择了一种HMG-CoA还原酶抑制剂的美维酸内酯衍生物，涉及syn1,3 -二醇单元。我们的手性恶唑硼烷酮促进了4-苯基丁醛与含有二硫烷的硅基烯酮缩醛的醛缩反应，从而产生了相应的乙酸醛，其对映选择性几乎完全。在相同的催化体系下，由第一个醛衍生的醛的第二次醛反应得到预期的-1,3-二醇。梅因内酯衍生物的合成非常容易。这是催化剂控制下对映选择性非环立体选择的一个很好的例子。

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.