作者:M. Mark midland、Alfonso tramontano、Aleksander kazubski、Richard S. graham、David J.S. tsai、Daniel B. cardin
DOI:10.1016/s0040-4020(01)82422-4
日期:1984.1
Propargyl ketones are readily reduced by the asymmetric reducing agent B-3-pinanyl-9- borabicyclo[3.3.1]-nonane (Alpine-borane). The reagent prepared from (+)-α-pinene and 9-BBN provides the R enantiomer while the S enantiomer can be obtained from (-)-α-pinene. Alternatively the S enantiomer can be prepared from the reagent derived from 9-BBN and the benzyl ether of nopol (6,6-dimethyl-bicyclo[3.11
炔丙基酮很容易被不对称还原剂B -3-pinanyl-9- borabicyclo [3.3.1]-壬烷(Alpine-borane)还原。由(+)-α-pine烯和9-BBN制备的试剂可提供R对映体,而S对映异构体可获自(-)-α-obtained烯。或者,S对映异构体可以由衍生自9-BBN和nopol的苄基醚(6,6-二甲基-双环[3.11。]庚-2-烯-2-乙醇)的试剂制备。获得高对映体诱导的限制因素通常是α--烯的对映体纯度。用100%对映体纯的α-pine烯,可获得基本上100%ee的炔丙醇。提出了导致这种显着选择的过渡态的预测合理化。炔丙醇的乙炔单元为转化为其他有用的旋光产物提供了方便的方法。说明了炔丙醇在合成光学活性的α-和β-取代的γ-内酯以及δ-内酯中的用途。