(R)-tert-Butoxycarbonylamino-fluorenylmethoxycarbonyl-glycine from (S)-Benzyloxycarbonyl-serine or from Papain Resolution of the Corresponding Amide or Methyl Ester
摘要:
The enantiospecific synthesis of (R)-Boc-(Fmoc)-aminoglycine 7 was achieved. (S)-Cbz-serine 1 was reacted with diphenylphosphoryl azide in the presence of triethylamine to yield cyclic (S) carbamate 2. The ring nitrogen of 2 was protected with a Boc group (3). The cyclic carbamate of 3, was hydrolyzed with benzyltrimethylammonium hydroxide to yield the (R)-enantiomer of alcohol. The oxidation of 4 with pyridinium dichromate yielded the enantiomerically pure (87% ee) (R)Boc-(Cbz)-aminoglycine 5, which was converted to 7 with retention of optical purity. Similarly, starting from (S)-Boc-serine 9, cyclic (S) carbamate 10 was obtained. The ring nitrogen of 10 was protected with a Cbz group (11) with retention of configuration. The cyclic carbamate of 11 was base hydrolyzed to yield 12, the (S)-enantiomer alcohol. Independently Boc-(Fmoc)-aminoglycine amide 13 and BoC-(Fmoc)-aminoglycine methyl ester 14 were resolved using papain. The stereochemistry of the isolated acid was determined to be (R) by coelution an HPLC of its. derivative, : with Marfey's reagent and that of-an authentic sample (7) obtained by enantiospecific synthesis.
(R)-tert-Butoxycarbonylamino-fluorenylmethoxycarbonyl-glycine from (S)-Benzyloxycarbonyl-serine or from Papain Resolution of the Corresponding Amide or Methyl Ester
摘要:
The enantiospecific synthesis of (R)-Boc-(Fmoc)-aminoglycine 7 was achieved. (S)-Cbz-serine 1 was reacted with diphenylphosphoryl azide in the presence of triethylamine to yield cyclic (S) carbamate 2. The ring nitrogen of 2 was protected with a Boc group (3). The cyclic carbamate of 3, was hydrolyzed with benzyltrimethylammonium hydroxide to yield the (R)-enantiomer of alcohol. The oxidation of 4 with pyridinium dichromate yielded the enantiomerically pure (87% ee) (R)Boc-(Cbz)-aminoglycine 5, which was converted to 7 with retention of optical purity. Similarly, starting from (S)-Boc-serine 9, cyclic (S) carbamate 10 was obtained. The ring nitrogen of 10 was protected with a Cbz group (11) with retention of configuration. The cyclic carbamate of 11 was base hydrolyzed to yield 12, the (S)-enantiomer alcohol. Independently Boc-(Fmoc)-aminoglycine amide 13 and BoC-(Fmoc)-aminoglycine methyl ester 14 were resolved using papain. The stereochemistry of the isolated acid was determined to be (R) by coelution an HPLC of its. derivative, : with Marfey's reagent and that of-an authentic sample (7) obtained by enantiospecific synthesis.
(<i>R</i>)-<i>tert</i>-Butoxycarbonylamino-fluorenylmethoxycarbonyl-glycine from (<i>S</i>)-Benzyloxycarbonyl-serine or from Papain Resolution of the Corresponding Amide or Methyl Ester
The enantiospecific synthesis of (R)-Boc-(Fmoc)-aminoglycine 7 was achieved. (S)-Cbz-serine 1 was reacted with diphenylphosphoryl azide in the presence of triethylamine to yield cyclic (S) carbamate 2. The ring nitrogen of 2 was protected with a Boc group (3). The cyclic carbamate of 3, was hydrolyzed with benzyltrimethylammonium hydroxide to yield the (R)-enantiomer of alcohol. The oxidation of 4 with pyridinium dichromate yielded the enantiomerically pure (87% ee) (R)Boc-(Cbz)-aminoglycine 5, which was converted to 7 with retention of optical purity. Similarly, starting from (S)-Boc-serine 9, cyclic (S) carbamate 10 was obtained. The ring nitrogen of 10 was protected with a Cbz group (11) with retention of configuration. The cyclic carbamate of 11 was base hydrolyzed to yield 12, the (S)-enantiomer alcohol. Independently Boc-(Fmoc)-aminoglycine amide 13 and BoC-(Fmoc)-aminoglycine methyl ester 14 were resolved using papain. The stereochemistry of the isolated acid was determined to be (R) by coelution an HPLC of its. derivative, : with Marfey's reagent and that of-an authentic sample (7) obtained by enantiospecific synthesis.