Alexander Pulis - Synthesis of Enantioenriched Tertiary Boronic Esters from Secondary Allylic Carbamates. Application to the Synthesis of C30 Botryococcene

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      Publication Details (including relevant citation   information):

      J.   Am. Chem. Soc. 2012,   134, 7570-7574

        A. P.   Pulis and V.   K. Aggarwal

      DOI:10.1021/ja303022d

      Abstract:

      Enantioenriched   secondary allylic carbamates have been deprotonated with sBuLi   and reacted with boronic esters. In contrast to other   electrophiles, high α-selectivity was observed and the boronate   complexes were formed with almost complete retention of   stereochemistry. The boronate complexes underwent a   stereospecific 1,2-migration leading to tertiary allylic boronic   esters with high er (>98:2). The scope of the reaction has   been explored and found to embrace a broad range of both allylic   carbamates and boronic esters. The methodology has been applied   to an eight-step, stereoselective synthesis of each of the   diastereoisomers of C30 botryococcene.

      Address (URL): http://pubs.acs.org/doi/abs/10.1021/ja303022d