Stereoselective Ring Expansion of Vinyl Oxiranes: Mechanistic Insights and Natural Product Total Synthesis
作者:Matthew Brichacek、Lindsay A. Batory、Jon T. Njardarson
DOI:10.1002/anie.200906830
日期:2010.2.22
applicable, catalytic, and stereoselective vinyl oxirane ringexpansion is described (see scheme; hfacac=hexafluoroacetylacetonate). The stereoselectivity was influenced by several reaction parameters, and kinetic studies support a mechanistic proposal involving the in situ formation of a more reactive catalytic species. This ring‐expansion reaction has been employed in the asymmetric total synthesis
The strategic marriage of method and motif. Total synthesis of varitriol
作者:Matthew Brichacek、Lindsay A. Batory、Nicholas A. McGrath、Jon T. Njardarson
DOI:10.1016/j.tet.2010.03.038
日期:2010.6
Detailed in this report are several new efficient synthetic approaches toward the natural product anti cancer agent varitriol, culminating in a concise total synthesis. A common theme for these routes is that they employ a new catalytic stereoselective vinyl oxirane ring expansion reaction, which provides rapid access to the common cis-2,5-tetrahydrofuran core. The combination of careful synthetic
Catalytic Regiodivergent Kinetic Resolution of Allylic Epoxides: A New Entry to Allylic and Homoallylic Alcohols with High Optical Purity
作者:Mauro Pineschi、Federica Del Moro、Paolo Crotti、Valeria Di Bussolo、Franco Macchia
DOI:10.1021/jo035674h
日期:2004.3.1
A novel regiodivergent kinetic resolution of a series of allylic epoxides with alkylzinc reagents is described. Results demonstrate the potential of chiral copper-phosphoramidite catalysts for enantiomer differentiation of allylic epoxides, allowing a chiral catalyst-stereoregulated synthesis of cyclic allylic and homoallylic alcohols with high optical purities.
A Regio- and Stereodivergent Route to All Isomers of <i>v</i><i>ic</i>-Amino Alcohols
作者:Berit Olofsson、Peter Somfai
DOI:10.1021/jo0262053
日期:2002.11.1
Vicinal amino alcohols are substructures in several important natural products. They are also frequently employed ligands in asymmetric synthesis. Many enantioselective syntheses of vic-amino alcohols have been reported, but each structure has required its own synthetic route. This study presents a synthetic strategy leading to all eight possible isomers of a given beta-amino alcohol, starting from vinyl epoxides. The developed strategy focuses on the propensity of vinyl epoxides and vinylaziridines to be selectively ring-opened at the allylic position by suitable hard nucleophiles. Within this strategy, a novel large-scale aminolysis reaction and the synthesis of a trisubstituted N-H vinylaziridine are detailed.