4 alpha-arylepicateching synthesis

4 alpha-arylepicateching synthesis

  • CN 100,358,885 C
  • Filed: 08/21/2001
  • Issued: 01/02/2008
  • Est. Priority Date: 09/05/2000
  • Status: Active Grant
First Claim
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1. one kind prepares l-Epicatechol-4 α

  • , the method for 8-l-Epicatechol dipolymer, and described method comprises following step;

    (a) with benzyl protecting group protection 5,7, the 3-hydroxyl of 3 '"'"', 4 '"'"'-four-O-benzyl l-Epicatechol forms 3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl l-Epicatechol;

    (b) the C-4 position of the l-Epicatechol of oxidation step (a) forms 3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl-4-hydroxyl l-Epicatechol;

    (c) the C-4 hydroxyl of the l-Epicatechol of oxidation step (b) formation (2R, 3S)-3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl-4-ketone l-Epicatechol;

    (d), add tert-butyl lithium in 3 '"'"', 4 '"'"'-five-O-benzyl-8-bromine l-Epicatechol and form shielded l-Epicatechol lithium reagent toward 3,5,7;

    (e) will form 3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl-4-hydroxyl-l-Epicatechol-4 α

    , 8-(3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl) l-Epicatechol dipolymer in the l-Epicatechol lithium reagent of l-Epicatechol adding from step (c) from step (d);

    (f) the C-4 hydroxyl with the dipolymer of step (e) is reduced into 3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl-l-Epicatechol-4 α

    , 8-(3,5,7,3 '"'"', 4 '"'"'-five-O-benzyl)-l-Epicatechol dipolymer;

    With(g) use the benzyl of the dipolymer of hydrogen step of replacing (f) to form l-Epicatechol-4 α

    , 8-l-Epicatechol dipolymer.

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