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DOI: 10.1055/sos-SD-203-00526

Oriyama, T.Science of Synthesis: Stereoselective Synthesis, (20113838.

Many effective methods for the kinetic resolution of racemic secondary alcohols with acid anhydrides and acid halides have been developed to give the corresponding optically active esters. However, the kinetic resolution using free carboxylic acids as acyl donors has great synthetic potential as numerous carboxylic acids, including aliphatic and aromatic types, are commercially available. For example, the kinetic resolution of a variety of racemic secondary benzylic alcohols to give optically active esters is possible using free carboxylic acids, benzoic anhydride, and a tetramisole-derived catalyst, which represents the first example of asymmetric acylation of racemic secondary alcohols with an achiral carboxylic acid.[‌38‌] The tetramisole derivative (+)-benzotetramisole [(+)-31; (+)-BTM] is prepared as outlined in Scheme 12.[‌39‌] In this procedure 2-chlorobenzo[d]thiazole (28) undergoes substitution with (R)-2-amino-2-phenylethanol (29) to give (R)-2-(benzo[d]thiazol-2-ylamino)-2-phenylethanol (30). This is followed by mesylation of the primary alcohol group and ring closure to give the catalyst.

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M8 M8 Meeeeeeeeee (e) ee (%) ee 88 Meeee (%) ee 88 ee (%) ee 88 Meeee (%) ee 88 Mee
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e-Me (MM8)8Me 88 88 88 88 88 [‌88‌]

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(M)-8-Meeeee-8-eeeeeeeeeeee 8-Meeeeeeeeeeeeeee [88, M8=eMe; M8=(MM8)8Me]; Meeeeee Meeeeeeee:[‌88‌]

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