Follow-up studies in our laboratory have shown that the absolute stereochemistry of deuterated substrate d-1a was incorrect. We initially assigned the absolute stereochemistry of d-1a to be (R)-isomer on the basis of the derivatization to the corresponding (R)- and (S)-MTPA esters, instead of the trichloroacetimidate moiety.1 We thoroughly checked the relationship between chemical shift differences and the corresponding MTPA esters of analogous deuterated compounds which were prepared from the enantioselective reduction of the corresponding enal-1-d using (R)-alpine borane reagent (the Midland reduction). On the basis of these careful investigations, we revised the absolute stereochemistry of d-1a to be the (S)-isomer. We also conclude that the modified Mosher method (derivatization to the MTPA ester) is not reliable, when assigning the absolute configuration of deuterated primary alcohols,2 such as d-1a. On the basis of the stereochemical revision, the mechanistic study section needs to be corrected as follows: Shigenobu Umemiya and Naoya Shinagawa are being added as authors because they clarified the stereochemical contradiction between the modified Mosher method and the enantioselective reduction using enantioenriched alpine borane reagent (the Midland reduction). Their careful investigations and considerations markedly contributed for this correction not only in the stereochemical assignment but also in the reaction mechanism.
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