کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1349304 980393 2005 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Univocal syntheses of 2- and 3-hydroxymethyl-2,3-dihydro[1,4]dioxino[2,3-b]pyridine enantiomers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Univocal syntheses of 2- and 3-hydroxymethyl-2,3-dihydro[1,4]dioxino[2,3-b]pyridine enantiomers
چکیده انگلیسی

The enantiomers of 2- and 3-hydroxymethyl substituted 2,3-dihydro[1,4]dioxino[2,3-b]pyridine 1 and 2, important chiral building blocks for the preparation of several biologically active compounds, were synthesized. (S)- and (R)-1 were obtained from either one or both the enantiomers of benzylglycerol, while (S)- and (R)-2 were obtained from (R)- and (S)-isopropylideneglycerol, respectively. The novel efficient synthetic strategies, which do not follow routes already reported for the corresponding racemates, ensure very high regioselectivity and maintenance of the enantiomeric purity of the starting materials. The enantiomeric composition of the title compounds was determined by chiral HPLC or NMR. The key intermediate in the synthesis of non-racemic 1, namely 1-benzyl-2-mesyl-3-tritylglycerol, is a new high melting chiral C3 synthon, worth considering for its stability, versatility, easy isolation by simple crystallization and, potential of configuration inversion through a simple one-pot reaction sequence.

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(R)-2-Hydroxymethyl-2,3-dihydro[1,4]dioxino[2,3-b]pyridineC8H9NO3Ee = 99.3% [by chiral HPLC][α]D25=+32.6 (c 0.5, EtOH)Source of chirality: (R)-1-benzylglycerolAbsolute configuration: R

(R)-3-Hydroxymethyl-2,3-dihydro[1,4]dioxino[2,3-b]pyridineC8H9NO3Ee >98% [by 1H NMR in the presence of a chiral solvating agent][α]D25=+28.1 (c 0.5, EtOH)Source of chirality: (R)-1-tosyl-2,3-isopropylideneglycerolAbsolute configuration: R

(S)-1-Benzyl-2-mesyl-3-tritylglycerolC30H30O5S[α]D25=-8.8 (c 1, CHCl3)Source of chirality: (R)-1-benzylglycerolAbsolute configuration: S

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tetrahedron: Asymmetry - Volume 16, Issue 20, 17 October 2005, Pages 3380–3384
نویسندگان
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