Organocatalytic Asymmetric Sequential 1,6-Addition/Acetalization of 1-Oxotetralin-2-carbaldehyde to <i>ortho</i>-Hydroxyphenyl-Substituted <i>para</i>-Quinone Methides for Synthesis of Spiro-3,4-dihydrocoumarins
作者:Zhi-Pei Zhang、Li Chen、Xin Li、Jin-Pei Cheng
DOI:10.1021/acs.joc.7b03177
日期:2018.3.2
A chiral squaramide catalyzed approach constructing spiro-3,4-dihydrocoumarin motif by the enantioselective 1,6-addition/acetalization reactions of 1-oxotetralin-2-carbaldehydes and ortho-hydroxyphenyl-substituted para-quinone methides followed by an oxidation was developed. The reactions proceeded smoothly with a wide range of p-QMs and 1-oxotetralin-2-carbaldehydes to generate corresponding products in high yields with excellent diastereoselectivities (>19:1 dr) and enantioselectivities (up to 99% ee).