Prins cyclization of 4-allyl-1,3-dioxanes prepared from 1,3-diol synthons. A rapid entry into functionalized tetrahydropyrans
摘要:
A variety of 4-allyl-1,3-dioxanes were prepared and cyclized to give 4-chloro or 4-acetoxy tetrahydropyrans in good yields and with high stereoselectivity. Copyright (C) 1996 Elsevier Science Ltd
Compounds of the general formula
A - B
where A is a carboxylic acid group having a carbon chain of 3-10 carbon atoms and preferably being branched, and which includes one or more oxo groups, and B is hydrogen, a pharmaceutically acceptable metal atom, an alcohol bound as ester and having 1-5 carbon atoms and 1-3 hydroxy groups, or a glycerol group bound as ester, can be used as a nutrient substrate, an antimicrobial and antiviral agent, and/or as an agent for influencing the central nervous system.
The invention also relates to compositions intended for the aforementioned usages and containing at least one compound A - B.
一般公式为 A - B 的化合物
其中 A 是一个具有 3-10 个碳原子的碳链的羧酸基团,最好是分支的,并且包括一个或多个氧代基团,B 是氢,一种药物上可接受的金属原子,一个作为酯键合的醇,有 1-5 个碳原子和 1-3 个羟基,或一个作为酯键合的甘油基团,可以用作营养底物,抗菌和抗病毒剂,以及/或作为影响中枢神经系统的剂。
该发明还涉及旨在上述用途并含有至少一个化合物 A - B 的组合物。
Temporary Silicon Connection Strategies in Intramolecular Allylation of Aldehydes with Allylsilanes
作者:Julien Beignet、Peter J. Jervis、Liam R. Cox
DOI:10.1021/jo800824x
日期:2008.7.1
dimethylsilyl ether connection between the aldehyde and allylsilane, with a range of Lewis and Brønsted acid activators provides an (E)-diene product. The mechanism of formation of this undesired product is discussed. Systems containing a sterically more bulky diethylsilyl ether connection react differently: thus in the presence of TMSOTf and a Brønsted acid scavenger, intramolecular allylation proceeds
Stereoselective Synthesis of 2,4,5-Trisubstituted Tetrahydropyrans Using an Intramolecular Allylation Strategy
作者:Peter J. Jervis、Benson M. Kariuki、Liam R. Cox
DOI:10.1021/ol061957v
日期:2006.9.1
A highly stereoselective route to 2,4,5-trisubstituted tetrahydropyrans is reported. The key step employs an intramolecular allylation of a (Z)-allylsilane onto an aldehyde under Bronsted acid activation. Complete 1,4-stereoinduction accounts for the formation of only two out of the possible four THP products. The level of 1,3-stereoinduction is optimal when the reaction is carried out in an apolar
Using a Temporary Silicon Connection in a Highly Stereoselective Synthesis of a New Class of Cyclic Allenylsilanes
作者:Liam R. Cox、Rui Ramalho、Julien Beignet、Alexander C. Humphries
DOI:10.1055/s-2005-918465
日期:——
Aldehyde 4 reacts in the presence of TMSOTf and an acid scavenger to provide the corresponding oxasilacycle 5 in very good yield and as a single diastereoisomer. The sense of 1,3-stereoinduction serves to introduce a 1,3-svn-diol relationship into the cyclic product. This is in accord with a previous study involving an analogous intramolecular allylation.
Obtention of 2,2-(diethoxy) vinyl lithium and 2-methyl-4-ethoxy butadienyl lithium by arene-catalysed lithiation of the corresponding chloro derivatives. Synthetic applications
precursors 5 and 6 instead of the less stable corresponding bromo derivatives 3 and 4. Condensation with carbonyl compounds leads to interesting synthetic applications such as a two steps synthesis of retinal 13 from β-cyclocitral 10.