Catalytic asymmetric synthesis of descurainin via 1,3-dipolar cycloaddition of a carbonyl ylide using Rh2(R-TCPTTL)4
作者:Naoyuki Shimada、Taiki Hanari、Yasunobu Kurosaki、Masahiro Anada、Hisanori Nambu、Shunichi Hashimoto
DOI:10.1016/j.tetlet.2010.10.036
日期:2010.12
A catalytic asymmetric synthesis of descurainin has been achieved by incorporating an enantioselective 1,3-dipolar cycloaddition, a stereoselective alkene hydrogenation, an oxidation with Fremy’s salt and a regioselective demethylation with NbCl5 as the key step. The 1,3-dipolar cycloaddition of a carbonyl ylide derived from tert-butyl 2-diazo-5-formyl-3-oxopetanoate with 4-hydroxy-3-methoxyphenylacetylene
通过结合对映选择性的1,3-偶极环加成反应,立体选择性的烯烃加氢反应,弗雷米氏盐的氧化反应和NbCl 5的区域选择性脱甲基反应作为关键步骤,可以实现去甲肾上腺素的催化不对称合成。在四(N-四氯邻苯二甲酰)(Ⅱ)存在下,由2-重氮-5-甲酰基-3-氧戊酸叔丁酯衍生的羰基内酯与4-羟基-3-甲氧基苯基乙炔的1,3-偶极环加成反应。R)-叔亮氨酸] Rh 2(R- TCPTTL)4,在95%ee中提供了8-氧杂双环[3.2.1]辛烷骨架。