An Iterative Procedure for the Synthesis of Conjugated ψ‐Chlorotrienoic and ‐tetraenoic Esters and Related Derivatives

Abstract

An iterative stereoselective procedure for the synthesis of isomers of conjugated ψ‐chlorotrienoic esters and ψ‐chlorotetraenoic esters as well as related conjugated ψ‐chloropolyenynoic esters is described, using readily available conjugated chlorodienol and chloroenynol derivatives as starting materials. The two‐step sequence studied is based on repetition of a one‐pot conjugated allylic alcohol oxidation/Wittig reaction followed by a reduction step. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Tandem Oxidation Processes Using Manganese Dioxide: Discovery, Applications, and Current Studies

“…This methodology has been extensively adopted by other groups (Scheme 15). 7,[26][27][28][29][30] Negishi's group used bromodiene 3 in a route to polyunsaturated macrolide antibiotics; 7 products 20 and 21 were employed to prepare insect pheromones; 26,27 bromodieneoate intermediate 22 was used in the total synthesis of the apoptosis-inducing natural product apoptolidin; 28 a range of ω-chloro-trienoic and tetraenoic esters including 23 were employed to prepare polyene natural product targets; 29 and adduct 24 was employed in synthetic approaches toward the marine natural product, cyclotheonamide. 30 In terms of the TOP homologation with "two-directional" substrates, Blackburn and Taylor prepared diethyl corticrocin using TOP-Wittig procedures twice, as shown in Scheme 16.…”

Tandem-, Domino- and One-Pot Reactions Involving Wittig- and Horner-Wadsworth-Emmons Olefination

“…One-pot oxidation-Wittig olefination reactions are also quite common [40,, especially when the carbonyl component is labile [89,97]. Often, the oxidant of choice is MnO 2 [40,[43][44][45][46][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97], although a number of reactions are known where transformations were carried with air oxygen using metals and metal oxides as catalysts [72][73][74][75][76][77][78]. As many Wittig-and HWE reactions tolerate metal catalysts, this allows the running of Wittig/HWE reactions in combination with metal catalyzed cross coupling reactions and olefinations such as Heck [114][115][116][117][118][119][120][121][122][123], Suzuki [111]…”