Substitution nucleophile d'acetates de cyclenols allyliques fonctionnels par des organometalliques en presence de sels cuivreux. Application a une synthese rapide de la (±)mitsugashiw alactone
作者:Hassen Amri、Monique Rambaud、Jean Villieras
DOI:10.1016/s0040-4020(01)81522-2
日期:1990.1
Substitution of functional allylic cycloalkenol acetates by Grignardreagents (primary , secondary, tertiary-alkyl, vinyl, aryl) in the presence of a catalytic amount (2.5% equivalent) of cuprous iodide at low temperature, gives high yields of various functional α-substituted cycloalkenes . The reaction can be applied to lithium enolates of esters and need no catalyst, but may be performed with HMPA
Efficient Synthesis of Bicyclic Lactones via Tungsten-Mediated Intramolecular Cycloalkenation
作者:Kwei-Wen Liang、Malapaka Chandrasekharam、Chien-Le Li、Rai-Shung Liu
DOI:10.1021/jo980728m
日期:1998.10.1
these functionalized tungsten-alkynols with BF(3).Et(2)O leads to intramolecular cycloalkenation, producing bicyclic tungsten-oxacarbeniums in high yields. Air oxidation of these oxacarbenium salts produces unsaturated bicyclic lactones in good yields. The lactone products include delta- and epsilon-lactones fused with five-, six- and seven-membered carbocyclic rings. The preceding bicyclic tungst
Concurrent resolution and oxidation of an allylic acetate and its utilization in the diastereocontrolled synthesis of some cyclopentanoid monoterpenes
作者:Hiroshi Nagata、Kunio Ogasawara
DOI:10.1016/s0040-4039(99)01321-0
日期:1999.9
Racemic endo-4-acetoxybicyclo[3.2.1]oct-2-ene furnishes enantiopure (+)-bicyclo[3.2.1]oct-3-en-2-one and its dihydro derivative leaving enantiopure (+)-endo-4-acetoxybicyclo[3.2.1]oct-2-ene in a phosphate buffer solution in the presence of a lipase (Candida antarctica) and palladium(II) chloride. Utilizing the products, a diastereocontrolled route to some cyclopentanoid monoterpenes has been established
Second Generation Palladium-Catalyzed Cycloalkenylation in Iridoid Lactone Synthesis: Total Syntheses of (±)-Onikulactone and (±)-Mitsugashiwalactone
作者:Masahiro Toyota、Megumi Saeki
DOI:10.3987/com-10-s(e)115
日期:——
Type-II iridoid lactones, onikulactone (1) and mitsugashiwalactone (2), were synthesized by employing the second generation palladium-catalyzed cycloalkenylation reaction as the key step.
Intramolecular carbocupration reaction of unactivated alkynes bearing a stabilized nucleophile: Application to the synthesis of iridoid monoterpenes
作者:Didier Bouyssi、Nuno Monteiro、Geneviève Balme
DOI:10.1016/s0040-4039(98)02630-6
日期:1999.2
The copper-promoted cycloisomerization of unsaturated alkynes bearing a stabilized nucleophile is described, providing a novel synthesis of various iridoid monoterpenes. (C) 1999 Elsevier Science Ltd. All rights reserved.