87248-50-8Relevant academic research and scientific papers
Chiral Lactols, V - The Synthesis of (S)-Benzoin from meso-Hydrobenzoin
Noe, Christian R.,Knollmueller, Max,Steinbauer, Gerhard,Voellenkle, Horst
, p. 4453 - 4458 (2007/10/02)
An efficient synthesis of enantiomerically pure (S)-benzoin is described.In the key step, which is a selective acetal formation reaction, a compound of type 1 (e.g. -octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-ol (1a)) reacts with the hydroxy group at the (S)-centre of meso-hydrobenzoin (2) to yield 79percent of the acetal 3a.This compound is oxidized using N-chlorosuccinimide/dimethyl sulfide to yield the ketone 4, from which enantiomerically pure 5 is obtained by treatment with acid.The selectivity observed in acetal formation is discussed.
Chiral Lactols, II. Racemate Separation and Enantioselective Acetalisation with the 2,3,3a,4,5,6,7,7a-Octahydro-7,8,8-trimethyl-4,7-methanobenzofuran-2-yl Protective Group
Noe, Christian R.
, p. 1591 - 1606 (2007/10/02)
A simple method for the resolution of the chiral alcohols, cyanohydrins, thiols and amines rac-2a - f by the reaction with the chiral protective group 1a ( or 1b, respectively) is described.The diastereomeric derivatives 3a - f and 4a - f are separated by column chromatography or crystallisation.Subsequent methanolysis or hydrolysis, respectively, yields the enantiomers and the recovered protective group.With rac-2a - c preferential acetalisation of the (R)-enantiomers was observed.This phenomenon was investigated by modification of the protective group.Considerations on conformations of 3a point to an important role of the anomeric and exo-anomeric effect in this enantioselective reaction.
