1137951-97-3Relevant academic research and scientific papers
Doubly diastereoselective conjugate addition of homochiral lithium amides to homochiral α,β-unsaturated esters containing cis- and trans-dioxolane units
Davies, Stephen G.,Durbin, Matthew J.,Goddard, Euan C.,Kelly, Peter M.,Kurosawa, Wataru,Lee, James A.,Nicholson, Rebecca L.,Price, Paul D.,Roberts, Paul M.,Russell, Angela J.,Scott, Philip M.,Smith, Andrew D.
supporting information; experimental part, p. 761 - 776 (2009/06/19)
As part of a long-term goal directed towards the ab initio asymmetric synthesis of unnatural amino sugars, the doubly diastereoselective conjugate addition reactions of the antipodes of lithium N-benzyl-N-(α-methylbenzyl) amide to a range of homochiral α,β-unsaturated esters containing cis- and trans-dioxolane units was investigated. These reactions resulted in "matching" and "mismatching" effects. In the "matched" cases a single diastereoisomer of the corresponding β-amino ester (containing three contiguous stereocentres) is produced. Upon conjugate addition to a homochiral α,β-unsaturated ester containing a cis-dioxolane unit, in the "mismatched" case it is the stereocontrol of the substrate which is dominant over that of the lithium amide, whilst upon addition to homochiral α,β-unsaturated esters containing a trans-dioxolane unit the stereocontrol of the homochiral lithium amide is dominant. Hydrogenolytic N-deprotection of the β-amino ester products of conjugate addition gives access to polyoxygenated β-amino acid derivatives.
