10.1021/jo401517q.s011 Hiroaki Shitara Hiroaki Shitara Toshiki Shintani Toshiki Shintani Koichi Kodama Koichi Kodama Takuji Hirose Takuji Hirose Solvent-Induced Reversed Stereoselectivity in Reciprocal Resolutions of Mandelic Acid and <i>erythro</i>-2-Amino-1,2-diphenylethanol American Chemical Society 2013 thermogravimetric analysis dioxane Reciprocal Resolutions sheetlike structure pseudopolymorphic salt crystals diastereomeric salt IR spectra erythro crystallization stereocontrol technique crystal structures 1 H NMR spectra resolution process equimolar amount 2013-09-20 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Solvent_Induced_Reversed_Stereoselectivity_in_Reciprocal_Resolutions_of_Mandelic_Acid_and_i_erythro_i_2_Amino_1_2_diphenylethanol/2374828 Solvent-induced chirality switching in reciprocal optical resolution between mandelic acid (<b>1</b>) and <i>erythro</i>-2-amino-1,2-diphenylethanol (<b>2</b>) has been demonstrated. The stereochemistry of the deposited salts was controlled by changing the crystallization solvent from 1-PrOH or 1-BuOH to 1,4-dioxane. It was revealed from <sup>1</sup>H NMR spectra, thermogravimetric analysis, and X-ray crystallography of the salts that an equimolar amount of the crystallization solvent was incorporated in each diastereomeric salt. On the basis of the crystal structures, it was found that both the hydrogen-bonding ability and the size of the solvent molecule played an important role. Differences in the formed hydrogen-bonding networks (columnar or sheetlike structure) and their packing manner were found to be crucial for the reversed stereoselectivity. Furthermore, pseudopolymorphic salt crystals that incorporated 1,4-dioxane were obtained during the enantioseparation of racemic <b>2</b>, and their solid-state properties were examined by measurement of their IR spectra. This solvent-induced dual stereocontrol technique was successfully applied to the successive resolution process, eliminating the need to change the resolving agent for access to both enantiomers of <b>1</b> and <b>2</b>.