Vinyl cyanide hydroxylation

Vinyl cyanides may be useful derivatives since permanganate-induced a-hydroxylation in the presence of alkenes has been demonstrated, e.g. (90) to (91). Oxygenation of a,B-unsaturated vinylsilanes and sulfides using the previously described procedures wo d not be successful (Sections 2.3.2.1. S.iii and 2.3.2.l.S.iv). However a singlet oxygen cycloaddition process (cf. Section 2.3.2.2.3.ii), followed by eliminative hydrolysis, could provide a usable, although lengthy, approach (Scheme 18). 

The hydroxyl group was usually protected, because cyanohydrins have tendency to racemization or even decomposition. Vinyl ethers or acetal and acid catalysts furnish acetals [62]. Trialkylsilyl chlorides and imidazole are used to give silyl ethers [63]. Commonly used protective groups are silyl ether, ester, methoxy isopropyl (MIP) ether, and tetrahydro-pyranyl ether. ( -Protected cyanohydrins are tolerant to a wider range of cyanide/nitrile transformations and are utilized widely in the synthesis of compounds of synthetic relevance in organic chemistry. 

Enzymatic desymmetrization of substituted 1,3-propanediols has been used as key step in the synthesis of y-butyrolactones by Itoh and coworkers, Scheme (8) [54],The diols 43 were treated with lipase PS (Pseudomenas sp.) in the presence of vinyl acetate as acyl donor to afford acetates 44 in excellent chemical yields and very high enantiomeric excesses (90-98%). These monoacetates were then converted into hydroxy nitriles 46 using a three step procedure. Tosylation of the hydroxyl group of 44, followed by treatment with potassium cyanide in dimethyl sulfoxide at 80°C gave the corresponding acetates 45. The acetoxy groups of 45 were finally hydrolysed with lithium hydroxide in a... 

The interest in functionalized ionic liquids is growing because ionic liquids bearing ether, amino or alcohol functionalities have been shown to display special properties, including the ability to dissolve a larger amoimt of metal halide salts and to extract heavy metal ions from aqueous solutions. Imidazolium-based ionic liquids with ether and hydroxyl (see Section 2.2.1), thiourea, thioether and urea (see Section 2.2.8) " have been prepared following the standard quatemization procedure. A straightforward approach has been described for the preparation of imidazolium (as well as pyridinium) cations with ester, ketone or cyanide functionalities 1-methylimidazole reacts with methanesulfonic acid to provide the imidazolium salt 11, which undergoes a Michael-type reaction with methyl vinyl ketone as a ,j8-unsaturated compound to produce the ionic liquid 12 (Scheme 5). ... 

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