that exchange of the hydroxyl protons by acid catalysis provides a useful method for the detection of intramolecular hydrogen bonds. The interpretation of exchange rates and coupling constants determines the direction of the H-bonds as conditioned by the relative acceptor and donor properties of the hydroxylgroups. The selectivity of the acylation agrees fully with the effectiveness of H-bonding networks
3-表位,4-表位和5-表位奎尼酸和sh草酸衍生物的选择性单官能化已通过南极假丝酵母脂肪酶A(CAL-A)的酶促酰化作用实现。我们建议这种脂肪酶的选择性与固有的受体选择性和配体中分子内氢键的程度有关。羟基质子的构象分析已由1进行。1 H NMR光谱。我们已经表明通过酸催化的羟基质子交换提供了一种检测分子内氢键的有用方法。交换率和偶合常数的解释决定了氢键的方向,该方向取决于羟基的相对受体和供体性质。酰化的选择性与多元醇化合物中H键网络的有效性以及赤道羟基的较高反应性完全吻合。
Brief syntheses of (±)-methyl shikimate, (±)-methyl epishikimate and structural variants
作者:Malcolm M. Campbell、Aston D. Kaye、Malcolm Sainsbury、Roya Yavarzadeh
DOI:10.1016/s0040-4020(01)83498-0
日期:1984.1
Synthesis and biological evaluation of new 6-s-cis locked 1,2,25-trihydroxyprevitamin D3 analogues
An efficient synthesis of several diastereomers of 2-hydroxy substituted 1 alpha,25-dihydroxyprevitamin D-3 derivatives was accomplished utilizing a practical route to the A-ring synthon. The biological activity of the analogues was evaluated in vitro. All the synthesized derivatives demonstrated low affinity for the vitamin D receptor and vitamin D-binding protein compared with 1 alpha,25-dihydroxyvitamin D-3, the natural hormone. 1 alpha,2 beta,25-trihydroxy-19-nor-pre-D-3 was the most potent of the analogues in inhibiting proliferation of MCF-7 cells but requires higher EC50 concentrations than lot,25-dihydroxyvitamin D-3. (C) 2007 Elsevier Ltd. All rights reserved.
Brief diels alder syntheses of (±)-methyl 5-epishikimate and (±)-methyl -3,4-dihydro-3,4-dihydroxybenzoate.
作者:Malcolm M. Campbell、Aston D. Kaye、Malcolm Sainsbury
DOI:10.1016/s0040-4039(00)86246-2
日期:1983.1
Complementary short syntheses of (±)-methyl shikimate
作者:Malcolm M. Campbell、Aston D. Kaye、Malcolm Sainsbury、Roya Yavarzadeh