The asymmetric synthesis of new tetrahydropyrrolo[2,3-b]indole 19 and tetrahydropyrano[2,3-b]indole 20 rings, substituted in position C-3a and C-4a with a hydroxy- and an amino functionalized chain, respectively, was performed starting from the racemic spiro[cyclohexane-1,3'-indoline]-2',4-diones 7. The enantiopure spiro oxo-azepinoindolinone (+)-10, obtained from (+/-)-7 by the way of an asymmetric ring enlargement, and the amino acid (+)-14, obtained by the hydrolysis of 10, were prepared as key intermediates for the synthesis of enantiopure compounds ( )-19 and ( )-20. Since the amino acid 14 is the common intermediate for the chemoselective preparation of derivatives 19 and 20, experimental and computational Studies were performed in order to selectively obtain these Compounds and to provide a mechanistic rationalization for their formation.
Chemoselective asymmetric synthesis of C-3a-(3-hydroxypropyl)tetrahydropyrrolo[2,3-b]indole and C-4a-(2-aminoethyl)tetrahydropyrano[2,3-b]indole derivatives
Pilati T;
2009
Abstract
The asymmetric synthesis of new tetrahydropyrrolo[2,3-b]indole 19 and tetrahydropyrano[2,3-b]indole 20 rings, substituted in position C-3a and C-4a with a hydroxy- and an amino functionalized chain, respectively, was performed starting from the racemic spiro[cyclohexane-1,3'-indoline]-2',4-diones 7. The enantiopure spiro oxo-azepinoindolinone (+)-10, obtained from (+/-)-7 by the way of an asymmetric ring enlargement, and the amino acid (+)-14, obtained by the hydrolysis of 10, were prepared as key intermediates for the synthesis of enantiopure compounds ( )-19 and ( )-20. Since the amino acid 14 is the common intermediate for the chemoselective preparation of derivatives 19 and 20, experimental and computational Studies were performed in order to selectively obtain these Compounds and to provide a mechanistic rationalization for their formation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
