Uses
Methyl (
S)-(+)-mandelate may be used in the preparation of (
S)-(-)2-hydroxy-1,2,2-triphenylethyl acetate and (α′
S)-α′-methoxycarbonylbenzyl (2
S,4
R)-(+)-1,2,4,5-tetrahydro-4-methyl-7,8-methylenedioxy-5-oxo-3-benzothiepin-2-carboxylate.
Synthesis
GENERAL METHOD: To a stirred solution of 0.1 mol α-acetoxymandelic acid or α-hydroxymandelic acid dissolved in 200 mL of anhydrous methanol at -30°C was slowly added 8.1 mL (13.05 g, 0.11 mol) of thionyl chloride. The reaction solution was continued to be stirred at -30°C for 15 minutes and then moved to room temperature for 48 hours. Upon completion of the reaction, the solvent was removed by concentration under reduced pressure. The residue was adjusted to pH 9 with NaHCO3 solution and subsequently extracted with ether (5 x 50 mL) and the organic phase was dried with MgSO4. After evaporation of the solvent, the resulting (S)-2-hydroxy-2-phenylacetic acid methyl ester crude was purified by either reduced pressure distillation or petroleum ether-toluene mixed solvent crystallization.
References
[1] Patent: JP2005/120020, 2005, A. Location in patent: Page/Page column 9
[2] Angewandte Chemie, International Edition, 2009, vol. 48, # 25, p. 4605 - 4609
[3] Angewandte Chemie, International Edition, 2014, vol. 53, # 37, p. 9860 - 9864,5
[4] Angewandte Chemie, 2014, vol. 126, # 37, p. 10018 - 10022,5
[5] Chemistry Letters, 1997, # 1, p. 55 - 56
