Enantioselective Aldol Reaction of Tetrasubstituted Ketene Silyl Acetals with Achiral Aldehydes for the Construction of Asymmetric Tertiary Alcohols: An Application for the Divergent Total Syntheses of Buergerinins F and G
作者:Isamu Shiina、Takashi Iizumi、Yu-suke Yamai、Yo-ichi Kawakita、Kazutoshi Yokoyama、Yo-ko Yamada
DOI:10.1055/s-0029-1216922
日期:2009.9
febrifuge agent having a unique trioxatricyclo[5.3.1.0¹,5]undecane skeleton, is stereoselectively prepared by means of the enantioselective aldol reactions via ten linear steps from crotonaldehyde in 18% overall yield including an effective intramolecular Wacker-type ketalization of the dihydroxy-γ-lactone as a key step. In addition to the former establishment for the synthesis of (+)-buergerinin F, effective
通过促进与手性二胺配位的三氟甲磺酸锡(II),得到相应的在α-位具有手性叔醇的醛醇,已开发出杂原子取代的乙烯酮甲硅烷基缩醛与非手性醛的不对称醛醇缩合反应。该反应已成功地用于从非手性材料开始构建buergerinins F和G的基本骨架。(+)-Buergerinin G,一种潜在的消炎和发热剂,具有独特的三氧三环[5.3.1.0¹ ,5十一烷骨架是通过对映选择性醛醇缩合反应通过十个线性步骤从巴豆醛立体选择性地制备的,总产率为18%,其中包括有效的分子内Wacker型缩酮化二羟基-γ-内酯作为关键步骤。除了以前的合成(+)-buergerinin F的设施外,还通过统一的光学活性羟醛型中间体开发了制备buergerinins F和G的有效分散方法,该中间体是由四取代的乙烯酮甲硅烷基乙缩醛与巴豆醛通过不对称的Mukaiyama aldol反应。 醛醇缩合反应-锡-手性胺催化剂-对映选择性-叔醇-乙烯酮甲硅烷基缩醛