Horner-Wadsworth-Emmons Reactions as a Facile Entry to Biogenetic Key Substructures
作者:Johann Mulzer、Andreas Sieg、Christoph Brücher、Dieter Müller、Harry J. Martin
DOI:10.1055/s-2005-863705
日期:——
One-pot Horner-Wadsworth-Emmons reactions are used to synthesize α,β-enones with two configurationally independent stereogenic centers. These intermediates are used for the construction of polyketide and monosaccaride fragments. In particular, novel approaches to the branched pentoses mycarose and arcanose are described.
Synthesis of Sundiversifolide and Diversifolide via a Diastereoselective [3+2] Nitrile Oxide Cycloaddition Reaction
作者:Kozo Shishido、Hiroyuki Sasaki、Hiromasa Yokoe、Mitsuru Shindo、Masahiro Yoshida
DOI:10.3987/com-08-s(f)67
日期:——
The enantioselective synthesis of the unnatural enantiomers (-)-sundiversifolide and (+)-diversifolide has been accomplished employing a diastereoselective intramolecular [3+2] nitrile oxide cycloaddition reaction as the key step.
Synthesis of Southern (C1'-C11') and Eastern (C8-C18) Fragments of Pamamycin-607, an Aerial Mycelium-inducing Substance of Streptomyces alboniger
Synthesis of the southern C1'-C11' and eastern C8-C18 fragments of pamamycin-607, an aerialmycelium-inducingsubstance of Streptomycesalboniger, was achieved. The southern fragment was synthesized by using the Evans aldol reaction and cis-selective iodoetherification as the key steps in a 9.6% overall yield (7 steps). The eastern fragment was constructed via the Julia coupling reaction and cis-selective
Formal totalsyntheses of (–)-indolizidines 205A, 207A, and 235B have been accomplished using Evans aldol, Horner–Wadsworth–Emmons olefination and reductive cyclization as key reactions.