کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1386242 | 982482 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Anomeric O-acylation of Kdo using alkyl and aryl isocyanates
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
To develop a convenient method for the preparation of an α-Kdo derivative carrying a functional spacer at the reducing end, we examined anomeric O-acylation using Kdo and halogenated alkyl/aryl isocyanates as nucleophile and electrophiles, respectively. Reaction of a Kdo derivative with 2-chloroethyl isocyanate in the presence of DMAP gave an α-spiro product (82%) and an α-Kdo derivative of a dimeric isocyanate adduct (10%). Similar reaction with 4-(chloromethyl)phenyl isocyanate gave only the corresponding α-spiro product (81%). The NMR data show that the pyranose rings of both the alkyl and aryl spiro products adopt the 5C2 conformation. Thus, we accomplished α-selective anomeric O-acylation by coupling the Kdo derivative with alkyl and aryl isocyanates.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Carbohydrate Research - Volume 340, Issue 17, 12 December 2005, Pages 2682-2687
Journal: Carbohydrate Research - Volume 340, Issue 17, 12 December 2005, Pages 2682-2687
نویسندگان
Tsuyoshi Ichiyanagi, Ryohei Yamasaki,