35468-63-4Relevant academic research and scientific papers
Mechanism of Hydrolysis of Hydroxy Thiolesters in the Presence of Boric Acid
Okuyama, Tadashi,Nagamatsu, Hiroaki,Fueno, Takayuki
, p. 1336 - 1342 (1981)
The catalytic effect of boric acid on the hydrolysis of S-butyl 2-hydroxy-2-phenylthioacetate (thiomandelate, 1) and 3-hydroxy-3-phenylthiopropionate (2) has been investigated in aqueous solution.The catalytic constants increased sigmoidally with increasing pH, the pKa of the curve being 9.2 for both 1 and 2.Approximate Hammett ρ values were 1.2 and 0.6 for the alkaline and borate-catalyzed hydrolyses of ring-substituted derivatives of 1, respectively.Boric acid did not show any specific influence on the hydrazinolysis of 1.Thise results lead to the conclusion that the borate catalysis occurs through an intramolecular transfer of the boron-coordinated hydroxide ion to the carbonyl carbon within a borate-substrate complex.
Highly stereoselective synthesis of chiral aldol polymers using repeated asymmetric Mukaiyama aldol reaction
Itsuno, Shinichi,Komura, Kenichi
, p. 8237 - 8246 (2007/10/03)
Asymmetric aldol polymerization of bis(triethylsilyl enol ether) and dialdehyde was performed in the presence of chiral N-sulfonyloxazaborolidinone as a catalyst. The polymerization occurred smoothly at low temperature (-78°C to -20°C) to afford optically active polymers having unique main-chain structure of β-hydroxy carbonyl repeating unit. In order to estimate the asymmetric induction during the polymerization, asymmetric aldol reaction of triethylsilyl enol ether and benzaldehyde was studied as a model reaction. Optical purity of the chiral polymers obtained from the asymmetric polymerization was determined by using 1H NMR analysis after their chiral derivatization with (R)-O-acetylmandelic acid.
