15898-68-7

Upstream product

• 34497-18-2 diethyl nona-2,7-diynedioate 
• 67081-18-9 ethyl (E)-7-oxohept-2-enoate 
• 1099-45-2 ethyl (triphenylphosphoranylidene)acetate 
• 1530-45-6 (carbethoxymethyl)triphenylphosphonium bromide 
• 111-30-8 Glutaraldehyde 

Relevant academic research and scientific papers

In situ generation of ylides for tandem oxidation-olefination reactions of unactivated diols

An efficient desymmetrization of diols is achieved using phosphonium salts which undergo deprotonation in the presence of a hindered amine base and manganese dioxide to produce α,β-unsaturated hydroxy esters in good yields. Georg Thieme Verlag Stuttgart.

Iron-mediated and -catalyzed metalative cyclization of electron- withdrawing-group-substituted alkynes and alkenes with grignard reagents

Treatment of ethyl (E)-5,5-bis[(benzyloxy)methyl]-8-(N,N-diethylcarbamoyl)- 2-octen-7-ynoate with an iron reagent generated from FeCl2 and tBuMgCl in a ratio of 1:4 (abbreviated as FeCl2/4 tBuMgCl) afforded ethyl [4,4-bis[(benzyloxy)methyl]-2-[(E)-(N,N-diethylcarbamoyl)methylene] cyclopent-1-yl]acetate in good yield. Deuteriolysis of an identical reaction mixture afforded the bis-deuterated product ethyl [4,4-bis[(benzyloxy)methyl]-2- [(E)-(N,N-diethylcarbamoyl)deuteriomethylene]cyclopent-1-yl]deuterioacetate, thus confirming the existence of the corresponding dimetalated intermediate. The latter intermediate can react with halogens or aldehydes to facilitate further synthetic transformations. The amount of FeCl2 was reduced to catalytic levels (10 mol% relative to enyne), and catalytic cyclizations of this sort proceeded with yields comparable to those of the aforementioned stoichiometric reactions. The cyclization of diethyl (E,E)-2,7-nonadienedioate with a stoichiometric amount of FeCl2/4 tBuMgCl, followed by the addition of sBuOH as a proton source, afforded a mixture of 2-(ethoxycarbonyl)- 3-bicyclo[3.3.0]octanone and its enol form in good yield. The use of aldehyde or ketone in place of sBuOH afforded 2-(ethoxycarbonyl)-3-bicyclo[3.3.0]octanone, which has an additional hydroxyalkyl side chain. Additionally, the metalation of a carbon-carbon unsaturated bond in N,N-diethyl-5,5-bis[(benzyloxy)methyl]-7,8- epoxy-2-octynamide or (E)-3,3-dimethyl-6-(N,N-diethylcarbamoyl)-5-hexenyl p-toluenesulfonate with FeCl2/4 tBuMgCl or FeCl2/4 PhMgBr was followed by an intramolecular alkylation with an epoxide or alkyl p-toluenesulfonate to afford 5,5-bis[(benzyloxy)methyl]-3-[(E)-(N,N- diethylcarbamoyl)methylene]-1-cyclohexanol or N,N-diethyl(3,3- dimethylcyclopentyl)acetamide after hydrolysis. In both cases, the remaining metalated portion α to the amide group was confirmed by deuteriolysis and could be utilized for an alkylation with methyl iodide.

Iron-mediated intramolecular metalative cyclization of α,β- unsaturated esters and amides. Versatile one-pot preparation of bicyclic ketoesters

(Chemical Equation Presented) 2-Nonen-7-ynedioic or 2-decen-8-ynedioic acid derivatives were treated with an iron reagent generated from FeCl2 and t-BuMgCl in a ratio of 1:4 to give cyclized products after hydrolysis, deuteriolysis, or the addition of carbonyl compounds. Upon reaction with the same iron reagent, 2,7-nonadienedioates afforded bicyclic ketoesters (and their enol forms) after the addition of s-BuOH or carbonyl compounds.

Diol desymmetrization as an approach to the synthesis of unsymmetrical dienyl diesters

The tandem oxidation/Wittig olefination of unactivated diols utilizing manganese dioxide produces α,β-unsaturated hydroxy esters in high yields in a highly effective desymmetrization process. The formation of small quantities of the corresponding lactones suggests that the reaction may proceed through a lactol intermediate in some cases. The α,β-unsaturated hydroxy esters are transformed into symmetrical or unsymmetrical dienyl diesters using a second oxidation/Wittig olefination sequence mediated by PCC.