20127-04-2

Upstream product

• 67-56-1 methanol 
• 108-94-1 cyclohexanone 
• 335645-39-1 2-(4-chlorobutyl)-2-ethoxy-1,3-dioxolane 
• 51354-68-8 5-chloro-1,1,1-triethoxy-pentane 
• 89569-57-3 ethyl δ-chlorovalerimidate hydrochloride 
• 6280-87-1 δ-chlorovaleronitrile 

Relevant academic research and scientific papers

Masked β-, γ- and δ-lithium ester enolates: Useful reagents in organic synthesis

The reaction of ω-chloro orthoesters 1 with lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5% molar) in the presence of different electrophiles [ButCHO, PhCHO, (CH2)5CO, Et2CO, PhCOMe, PhCH=NPh, Me3SiCl] in THF at -78°C leads, after hydrolysis and acid-catalysed methanolysis, to functionalised methyl esters 2. In the case of chlorotrimethylsilane, hydroxyethyl esters 2′ are isolated. The reaction is also applied to bicyclic orthoesters 3: whereas β-chloro derivatives and carbonyl compounds gives directly γ-lactones 4 after hydrolysis, the corresponding γ-chloro derivative affords the expected methyl esters after methanolysis.

Masked ω-lithio ester enolates: Synthetic applications

The protocol of lithiation by means of lithium and a catalytic (5% molar) amount of DTBB (4,4'-di-tert-butylbiphenyl), applied to ω-chloro ortho ester 6 under Barbier-type conditions gives, after final acid-catalyzed methanolysis, the corresponding functionalized esters 8 or 9 (for chlorotrimethylsilane as electrophile) or, after ortho ester deprotection and acid catalyzed treatment, the δ-lactones 11. The procedure is also practical for bicyclic ortho esters 14: the β-chloro OBO ester derivate generates the γ-lactones 15 and the γ-chloro OBO ester gives corresponding esters 8.