Access to 2,4-Dien-6-ynoic Acid Esters Using Selenium Chemistry. Formal Synthesis of Z,Z-Dodeca-3,6-dien-1-ol (Trail Pheromone Mimic of the Subterranian Termite Reticulitermes virginicus) and Z,Z-Dodeca-3,6-dien-11-olide (Aggregation Pheromone of the Grain Beetles Oryzaephilus mercartor and O. surinamensis)
作者:Andrei A. Vasil'ev、Lars Engman、Edward. P. Serebryakov
DOI:10.1039/a802761g
日期:——
Esters of 2,4-dien-6-ynoic acids were prepared from terminal acetylenes by lithiation, 1,2-addition to acrolein, orthoester Claisen–Johnson rearrangement and α-(4-methoxyphenyl)selenation/oxidative elimination to introduce the α,β-unsaturation.
Iridium‐Catalyzed Chemo‐, Diastereo‐, and Enantioselective Allyl‐Allyl Coupling: Accessing All Four Stereoisomers of (
<i>E</i>
)‐1‐Boryl‐Substituted 1,5‐Dienes by Chirality Pairing
We report an iridium-catalyzed highly chemo-, diastereo-, and enantioselective allyl-allylcoupling between branched allyl alcohols and α-silyl-substituted allylboronate esters resulting in enantioenriched (E)-1-boryl-substituted 1,5-dienes. All four stereoisomers with two adjacent chiral centers were obtained by chirality pairing. Mechanistic studies were conducted to understand the high levels of
Synthesis of polysubstituted thiophenes by a catalytic cyclisation of functionalised episulfides
作者:Charles M. Marson、Jonathan Campbell
DOI:10.1016/s0040-4039(97)01819-4
日期:1997.11
Substituted thiophenes are formed by the reaction of 1-alkynyl-2,3-epithioalcohols with a catalytic amount of mercury(II) prepared from HgO and dilute sulfuric acid. (C) 1997 Elsevier Science Ltd.