Z-Selective Intramolecular Horner−Wadsworth−Emmons Reaction for the Synthesis of Macrocyclic Lactones
摘要:
When the substrates (ArO)(2)P(O)CH2CO2-CHO (Ar = Ph, o-t-BuPh) were added to a THF solution containing 3 equiv of NaH at 0 degrees C or NaI-DBU at rt over 1-10 h, the Intramolecular Horner-Wadsworth-Emmons reaction proceeded efficiently to give the 12-18-membered-ring lactones in 69-93% yields with 89-100% Z selectivity. On the other hand, (EtO)(2)P(O)CH2CO2-CHO gave the 13-18-membered-ring lactones in 52-82% yields with 89-99% E selectivity using LiCl-DBU in MeCN or THF.
Free radical macrocyclisation via propiolate esters.
作者:Jack E. Baldwin、Robert M. Adlington、Steve H. Ramcharitar
DOI:10.1016/0040-4020(92)85015-7
日期:1992.1
Intramolecular free-radical addition to propiolate esters has provided a new and a stereoselective route to 14–16 membered -α,β-unsaturated macrocylic lactones from their corresponding ω-iodoalkyl-propionate esters under triphenyltin hydride/AIBN mediated conditions. Attemps to synthesise analogous 10–13 membered lactones proved unsuccessful, resulting in acyclic products derived from direct reduction at the
Kumulierte Ylide XX.<sup>1</sup>Synthesen (<i>E</i>)-α,β-ungesättigter macrocyclischer Lactone durch intramolekulare Wittig-Olefinierung via Triphenylphosphoranylidenketen<sup>2</sup>
作者:Hans Jürgen Bestmann、Rainer Schobert
DOI:10.1055/s-1989-27271
日期:——
Cumulated Ylides XX.1 Syntheses of (E)-α,β-Unsaturated Macrocyclic Lactones by Intramolecular Wittig-Olefination via Triphenylphosphoranylideneketene2 Two methods for closure of macrocyclic lactone rings by intramolecular Wittig reaction of (Ï-oxoalkoxy)carbonylmethylenetriphenylphosphoranes are described. The latter are easily accessible by addition of the appropriate (free or protected) Ï-hydroxyalkanals to the cumulated ylide triphenylphosphoranylideneketene. Examples are then given for the use of these methods in natural product synthesis.
6-methoxy-2,6-dimethyloctanal and its use as a fragrance ingredient
申请人:Givaudan S.A.
公开号:EP1764355A1
公开(公告)日:2007-03-21
6-Methoxy-2,6-dimethyloctanal, a method of its production and fragrance compositions comprising it.
6-甲氧基-2,6-二甲基辛醛,其生产方法和含有它的香精组合物。
PROCESS FOR THE PREPARATION OF METHOXYMELONAL
申请人:Givaudan S.A.
公开号:US20140357547A1
公开(公告)日:2014-12-04
A process of forming methoxymelonal comprising the steps of treating a solution of citronellene to ozonolysis, and hydrogenating the product formed to provide methoxymelonal.
形成甲氧基美龙醛的过程包括处理柠檬烯溶液进行臭氧化反应,然后加氢处理生成的产物以得到甲氧基美龙醛。
[EN] PROCESS FOR THE PREPARATION OF METHOXYMELONAL<br/>[FR] PROCÉDÉ POUR LA PRÉPARATION DE MÉTHOXYMÉLONAL
申请人:GIVAUDAN SA
公开号:WO2013053787A1
公开(公告)日:2013-04-18
A process of forming methoxymelonal comprising the steps of treating a solution of citronellene to ozonolysis, and hydrogenating the product formed to provide methoxymelonal.