DETERMINATION OF THE GAUCHE EFFECT OF 3-ACETAMIDO-PIPERIDINE AND 3-ACETOXY-PIPERIDINE AND 3-ACETOXYTETRAHYDROPYRAN BY H-1-NMR SPECTROSCOPY

被引：24

作者：

BERNET, B

PIANTINI, U

VASELLA, A

机构：

[1] Organisch-Chemisches Institut der Universität Zürich, CH-8057 Zürich

来源：

CARBOHYDRATE RESEARCH | 1990年 / 204卷

关键词：

D O I：

10.1016/0008-6215(90)84017-O

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The A-values of the acetamido and the acetoxy group were determined by low-temperature 1H-n.m.r. spectroscopy. The limiting values for the relevant vicinal coupling constants of the newly prepared trans- (22) and cis-5-acetoxy-2-(1-hydroxy-1-methylethyl)tetrahydropyran (24) were obtained at room temperature. The attractive gauche effect of AcNH-3 and AcO-3 in piperidines, piperidinium trifluoroacetates, and tetrahydropyrans was investigated by 1H-n.m.r. spectroscopy both at low temperature (integrals) and at room temperature (band widths and coupling constants). The results obtained at low temperature are more reliable. The position of the conformational equilibrium of N-(3-piperidyl)acetamide (11), N-(1-methyl-3-piperidyl)acetamide (12), and N-(tetrahydropyran-3-yl)acetamide (17) [but not of 3-acetoxy-1-methylpiperidine (8) and 3-acetoxytetrahydropyran (15)] depends strongly upon the nature of the solvent and, in apolar solvents, upon the concentration. © 1990.

引用

页码：11 / 25

页数：15

共 33 条

[1] CONFORMATIONAL-ANALYSIS OF INTRAMOLECULAR HYDROGEN-BONDED AMINO-ALCOHOLS - DETERMINATION OF NH-N-ELECTRON PAIR EQUILIBRIUM AND ASSIGNMENT OF CONFORMATIONAL FREE-ENERGIES FOR INTERACTIONS IN DECAHYDROQUINOLINE AND PIPERIDINE COMPOUNDS IN A DILUTE NONPOLAR MEDIUM [J].