199341-50-9

Upstream product

• 184834-31-9 [-(2-methoxy-2-oxoethyl)-5-oxo-1,3-dioxolan-4-yl]acetic acid 
• 77862-72-7 (5-oxo-[1,3]dioxolane-4,4-diyl)-bis-acetic acid dimethyl ester 
• 77-92-9 citric acid 
• 144-16-1 5-oxo-1,3-dioxolan-4-ylidenedi(acetic acid) 
• 4767-12-8 4,4-(5-oxo-1,3-dioxolane)diacetic acid anhydride 

Downstream Products

• 77-93-0 citric acid triethyl ester 

Relevant academic research and scientific papers

Regio- and enantioselectivity of the enzyme-catalyzed hydrolysis of citric acid derivatives

The hydrolysis of triethyl citrate in the presence of three serine proteases (chymotrypsin, subtilisin BPN', subtilisin carlsberg) is highly regioselective and gives the symmetric diester. Several lipases and proteases have the complementary regioselectivity and give the chiral diester. Pig liver esterase, Aspergillus niger lipase and Candida antarctica lipase give the chiral (R)-diester with good regio- and enantioselectivity. The stereoselective hydrolysis of the meso citric derivatives 7a,b in the presence of Candida antarctica lipase gives the corresponding (R)-monoester.

Resolution of a citric acid derivative: Synthesis of (R)-(-)-homocitric acid-γ-lactone

Both the (R) and (S) enantiomers of the citric acid derivative 1 have been obtained in ≤90% ee via resolution of the racemate by fractional crystallisation of the (S) and (R)-α-methylbenzylamine salts respectively. The stereochemistry of (R)-1 has been assigned by its conversion to (R)-(-)- homocitric acid utilising an Amdt-Eistert homologation followed by acid eatalysed deprotection.