Synthesis of <i>trans</i>
-Configured Enol Ethers by a Sequence of <i>syn</i>
-Selective Glycolate Aldol Addition, Hydrolysis, and Grob Fragmentation
作者:Tobias Engesser、Reinhard Brückner
DOI:10.1002/ejoc.201701197
日期:2017.10.17
which delivered trans-configured enol ethers. Applying our 3-step sequence in a bidirectional synthesis led to bis(enol ethers) trans,trans-selectively, i. e., to a motif rarely encountered in the literature. A modified precursor synthesis allowed for the first time to access both the E- and the Z-isomer of an enol ether with a trisubstituted C=C bond stereoselectively using a Grob fragmentation route.
Double diastereoselective SuperQuat glycolate aldol reactions: Application to the asymmetric synthesis of polyfunctionalised lactones
作者:Stephen G. Davies、Rebecca L. Nicholson、Andrew D. Smith
DOI:10.1039/b411724g
日期:——
Polyfunctionalised lactones with up to five contiguous stereocentres may be prepared with high stereocontrol by a double diastereoselective aldol protocol with protected homochiral α,β-dihydroxy- or α,β-γ-trihydroxyaldehydes and a chiral glycolate oxazolidinone, followed by subsequent O-desilylation and lactonisation.