54074-85-0Relevant articles and documents
Cobalt-Catalyzed Alkoxycarbonylation of Epoxides to β-Hydroxyesters
Xu, Jian-Xing,Wu, Xiao-Feng
, p. 9907 - 9912 (2019/08/26)
Herein, we developed a new and practical catalytic system for the carbonylative synthesis of β-hydroxyesters. By using simple, cheap, and air-stable cobalt(II) bromide as the catalyst, combined with pyrazole and catalytic amount of manganese, active cobalt complex can be generated in situ and can catalyze various epoxides to give the corresponding β-hydroxyesters in moderate to excellent yields. Mechanism studies indicate that pyrazole plays a crucial role in this reaction. Moreover, with the addition of the catalytic amount of manganese, the active cobalt catalyst can be regenerated, which provides a possibility for reusing the cobalt catalyst.
Efficient large scale stereoinversion of (R)-ethyl 3-hydroxybutyrate
Carnell, Andrew J.,Head, Robert,Bassett, Derek,Schneider, Michael
, p. 821 - 825 (2007/10/03)
A three step method for the large scale preparation of enantiomerically pure ethyl (S)-3-hydroxybutyrate is reported starting from the commercial biopolymer poly[(R)-hydroxybutyrate]. The key step depends on the ability to cleanly invert the stereochemistry of (R)-ethyl 3-hydroxybutyrate via its mesylate ester under neutral conditions, avoiding the competing elimination process. This has been achieved in good (75%) yield on >100g scale by controlled addition of the mesylate to a stirred slurry of calcium carbonate in water at 80°C.