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

Alexander P. Pulis, Varinder K. Aggarwal*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

64 Citations (Scopus)

Abstract

Enantioenriched secondary allylic carbamates have been deprotonated with sBuLi and reacted with boronic esters. In contrast to other electrophiles, high alpha-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.

Original languageEnglish
Pages (from-to)7570-7574
Number of pages5
JournalJournal of the American Chemical Society
Volume134
Issue number17
DOIs
Publication statusPublished - 2 May 2012

Keywords

  • METALATED NITROGEN DERIVATIVES
  • HOMOALDOL REACTION
  • ORGANIC-SYNTHESIS
  • ENANTIOSELECTIVE SYNTHESIS
  • ALKENE-1,1-DIBORONIC ESTERS
  • TETRASUBSTITUTED OXIRANES
  • STEREOSELECTIVE-SYNTHESIS
  • STABILIZED CARBANIONS
  • HOMOENOLATE REAGENTS
  • ASYMMETRIC-SYNTHESIS

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