Enantioselective Reaction of Diketene to Aldehydes Promoted by Chiral Titanium Complexes

光学活性的5-羟基-3-氧代酯可以转化为6-取代的4-羟基内酯，其是已知为3-羟基-3-甲基戊二酰辅酶A（HMG-CoA）还原酶抑制剂的康伐他汀和美维诺林的常见结构组分。我们最近成功地通过新型手性Schiff碱钛醇盐配合物促进的双烯酮与醛的不对称反应高效制备了光学活性的5-羟基-3-氧代酯。这一新方法提供了一种合成光学活性5-羟基-3-氧代酯的有效方法，其对映体过量（ee）高达92%。

Optically Active 5-hydroxy-3-oxoesters can be converted into 6-substituted 4-hydroxy lactones which are common structural components of compactin and mevinolin known as inhibitors of 3-hydroxy-3-methylglutaryl Coenzyme A (HMG-CoA) reductase. W e recently succeeded in the highly efficient preparation of optically active 5-hydroxy-3-oxoesters by enantioselective reaction of diketene with aldehydes promoted by novel chiral Schiff basetitanium alkoxide complexes. This new procedure provides an efficient method for the synthesis of optically active 5-hydroxy-3-oxoesters in up to 92% enantiomeric excess (ee).