کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5272370 1385462 2009 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Enantiopure alkaloid analogues and iminosugars from proline derivatives: stereocontrol in sequential processes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Enantiopure alkaloid analogues and iminosugars from proline derivatives: stereocontrol in sequential processes
چکیده انگلیسی

An alternative to the use of expensive auxiliaries or catalysts in the synthesis of chiral 2-substituted pyrrolidines is described. Thus, commercial, cheap 4-(S)-hydroxyproline was readily transformed into optically pure pyrrolidines, using a one-pot decarboxylation-alkylation reaction as the key step. In this reaction, an acyliminium intermediate was generated, which was trapped by carbon nucleophiles. As postulated by Woerpel, the addition of the nucleophiles to the five-membered ring iminium ions took place stereoselectively, affording 2,4-cis-disubstituted pyrrolidines in high de. The hydroxy group at C-4 can then be removed, or alternatively, it can be used to create new functionalities in the molecule. In this way, optically pure alkaloid analogues and iminosugars were prepared.

In a few steps, enantiopure alkaloid analogues and iminosugars were obtained from inexpensive hydroxyproline derivatives. As postulated by Woerpel, 2,4-cis-pyrrolidines were formed in high de due to stereoelectronic effects.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron Letters - Volume 50, Issue 27, 8 July 2009, Pages 3974-3977
نویسندگان
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