137693-53-9

Upstream product

• 15356-60-2 (1S,2R,5S)-(+)-menthol 
• 137601-33-3 C₁₀H₁₆O₃ 
• 137601-32-2 (2Z)-2-methyl-2-butenoic 2,4,6-trichlorobenzoic anhydride 
• 35660-94-7 (Z)-2-methyl-2-butenoyl chloride 
• 565-63-9 Angelic acid 

Relevant academic research and scientific papers

Enantioselective preparation of (2R,3R)-(+)- and (2S,3S)-(-)-2,3-epoxy- 2-methylbutanoic acids and some derivatives

(2R,3R)-(+)- and (2S,3S)-(-)-2,3-epoxy-2-methylbutanoic acids (epoxyangelic acids) were prepared from (Z)-2-methyl-2-butenoic acid using the Sharpless asymmetric epoxidation method in combination with the use of (- )- and (+)-menthol as chiral auxiliaries. Both substances, obtained in high enantiomeric excess, were characterized by spectroscopic and optical activity data. Their absolute configuration was determined by correlation with (R)- (+)-2-methyl-1,2-butanediol.

Improved preparation of angelate esters

A new procedure has been developed for the efficient preparation of angelate esters from alcohols. The alcohol is treated in dry toluene at 70-80°C for 19-36 h with a mixed anhydride prepared from angelic acid and 2,4,6-trichlorobenzoyl chloride. In the absence of base, no tiglate ester is produced.