Selective epoxidation of monoterpenes with methyltrioxorhenium and H2O2
作者:Aída L.P. de Villa、Dirk E. De Vos、Consuelo C. de Montes、Pierre A. Jacobs
DOI:10.1016/s0040-4039(98)01853-x
日期:1998.11
terpenes such as α-pinene with H2O2 with minimal rearrangement of the epoxide. Pyridine is also critical to suppress isomerisation of the olefin substrate (in case of nerol, geraniol). The reaction can be directed towards selective single or double epoxidation, or in one step towards the rearranged product (e.g. from linalool to the ring-closure product linalool oxide).
在吡啶作为助催化剂的存在下,CH 3 ReO 3以最小的环氧基重排催化H 2 O 2对萜烯(如α-pine烯)的环氧化。吡啶对于抑制烯烃底物的异构化也是至关重要的(如果是神经醇,香叶醇)。该反应可以针对选择性的单或双环氧化,或在一步中针对重排的产物(例如从芳樟醇到闭环产物芳樟醇氧化物)。
Regioselective epoxidation of allylic alcohols with monoperoxyphthalic acid in water
The epoxidation of olefinic alcohols in water only has been investigated. Simple allylic alcohols are epoxidized readily and with high yields by m-chloroperoxybenzoic acid. Polyolefinic alcohols are epoxidized regioselectively and with excellent yields by monoperoxyphthalic acid controlling the pH of the medium. The reactions have been carried out in the presence and absence of surfactants, and their role has been investigated.
Selective epoxidation of monoterpenes with H2O2 and polymer-supported methylrheniumtrioxide systems
A convenient and efficient synthesis of monoterpene epoxides by application of heterogeneous poly(4-vinylpyridine)/methyl rhenium trioxide (PVP/MTO) and poly styrene/methyl rhenium trioxide (PS/MTO) systems is described. Even highly sensitive terpenic epoxides were obtained in excellent yield. Environment friendly, easily available, and low cost H2O2, was used as oxidant. Catalysts were stable systems for at least five recycling experiments. (C) 2003 Elsevier Ltd. All rights reserved.