Diarylprolinol‐Mediated Asymmetric Direct Cross‐Aldol Reaction of α,β‐Unsaturated Aldehyde as an Electrophilic Aldehyde
作者:Yujiro Hayashi、Kaito Nagai、Shigenobu Umemiya
DOI:10.1002/asia.201901236
日期:2019.12.2
The diarylprolinol-mediated asymmetric direct cross-aldol reaction of α,β-unsaturated aldehyde as an electrophilic aldehyde was developed. The reaction becomes accelerated by an acid when a carbonyl group is introduced at the γ-position of the α,β-unsaturated aldehyde. Synthetically useful γ,δ-unsaturated β-hydroxy aldehydes were obtained with high anti-selectivity and excellent enantioselectivity
A convergent synthesis of the meso-ter(1,3-dioxanyls) 8-11 has been achieved, starting from two enantiomeric building blocks in each case. The stereogenic centres in the central linkage region were set up by stereocontrolled aldol additions. Structure assignment of the final products was based on comparisons between experimental and calculated (3)J(H,H) coupling constants, which reflect distinct conformer populations. (C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.