tocopherol ESI v6 FINAL - Royal Society of · PDF...

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Transcript of tocopherol ESI v6 FINAL - Royal Society of · PDF...

  • Supplementary  Information  for:    

     

    Highly  stereoselective  construction  of  the  C2  stereocentre  of  α-­‐tocopherol  (vitamin  E)  by   asymmetric  addition  of  Grignard  reagents  to  ketones  

    Bartosz  Bieszczad  and  Declan  G.  Gilheany*  

     

     

    Centre  for  Synthesis  and  Chemical  Biology,  School  of  Chemistry  

    University  College  Dublin,    

    Belfield,  Dublin  4,  Ireland  

    Email:  declan.gilheany@ucd.ie    

     

    Contents:  

    1. General  experimental..............................................................................................................2  

    2. NMR  spectra  of  products  and  intermediates..........................................................................2  

    3. Chromatograms  of  1-­‐(2,5-­‐dimethoxy-­‐3,4,6-­‐trimethylphenyl)-­‐3,7,11,15-­‐ tetramethylhexadecan-­‐3-­‐ol  (1)..............................................................................................12  

     

     

     

     

     

     

     

     

     

     

     

     

    Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry. This journal is © The Royal Society of Chemistry 2017

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    1. General  Experimental    

     

    All  chemicals  were  supplied  by  Aldrich  apart  from  natural  phytol,  which  was  supplied  by  Wuhan  ChemFaces  

    Biochemical   Co.   Microwave   assisted   reactions   were   performed   using   CEM   Discover   microwave   instrument   (S-­‐

    series).   Supercritical   Fluid   Chromatography   (SFC)   analysis   was   made   using   ACQUITY   UPC2   system   with   auto-­‐

    sampler,   combined  with   PDA  Detector   Type  UPLC   eLambda   800   nm.   Chiral   column   Chiralpak®   IA-­‐3   of   internal  

    diameter  of  4.6  mm,  100  mm  with  particles  size  of  3  µm  was  used  to  separate  diastereoisomers  in  a  single  case  

    with  methanol  as  a  co-­‐solvent.  Samples  were  prepared  in  heptanes  in  approximately  1  mg/mL.  All  NMR  analysis  

    was  performed  using  300,  400  or  500  MHz  Varian  spectrometers.  NMR  samples  were  made  in  CDCl3.   1H  and  13C  

    NMR  chemical  shifts  are  given  relative  to  tetramethylsilane.  

     

    2. NMR  spectra  of  products  and  intermediates  

     

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    3. Chromatograms  of  1-­‐(2,5-­‐dimethoxy-­‐3,4,6-­‐trimethylphenyl)-­‐3,7,11,15-­‐ tetramethylhexadecan-­‐3-­‐ol  (1)  

    (i)  SCF  Chromatograms  of  high  dr  materials  from  Route  3  

    a) (R,R,R)  and  (S,R,R)  –  (50  :  50  dr)  

     

     

    b) (S,R,R)  –  diastereoisomer  –  95  :  5  dr  

     

     

    c) (R,R,R)  –  diastereoisomer  –  96  :  4  dr  

     

     

    (ii)  Best  HPLC  Chromatograms  (OJH  column,  resolution  =  0.4)  

    a)   (R,R,R)  and  (S,R,R)  –  (50  :  50  dr)  :  

     

     

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    b)   (R,R,R)  –  diastereoisomer  of  high  dr  from  Route  3  

     

     

    c)   (R,R,R)  –  diastereoisomer  of  moderate  dr  from  Route  2  

     

     

    (iii)  SCF  Chromatogram:  (S,R,R)  –  diastereoisomer  of  moderate  dr  from  Route  1