Sugar thiocarbamates

The kinetics of the reaction of hydroxyl groups of monosaccharides and polyols with benzyl isothiocyanate has been checked by Augustin and Balaz using UV spectroscopy.289 However, because of the reversibility of the reaction, this procedure is not. of synthetic utility. O-Sugar thiocarbamates have been more conveniently prepared by aminolysis of thiocarbonate derivatives290,291 or by thiocarbamoylation of free hydroxy] groups with 1,1 -tbiocarbonyldiimidazoie.7 286 288... 

The hydroxy groups in natural products like, for example, the macrolide antibiotics erythromycin, 1"1 and desmycosin, 2001 2011 as well as the 3-(hydroxymethyl)-2- or 3-cephems 2021 and derivatives of the amino sugar garamin 2031 have been converted into the carbamate function with CDI and amines. In the case of aminoglycoside antibiotics of the sisomicin series, thiocarbamates or dithiocarbamates have been prepared from alcohols or thiols using ImCSIm and amines.12041... 

The preparation and reactions of V-thiocarbonyl carbohydrate derivatives, such as sugar isothiocyanates, thioamides, thioureas, thiocarbamates and their conjugates have been the subject of valuable comprehensive as well as specialized accounts, which should be consulted for details.198... 

Radical deoxygenation of sugars can be realized with suitable alcohol derivatives such as esters (acetates, pivaloates), sulfur compounds (xanthates, thiocarbamates, tri-fluoromethylsulfonates) according to the general Scheme 41. 

Bitter taste is elicited by structurally diverse compounds, including phenols, ions, amino acids and peptides, alkaloids, acylated sugars, glycosides, nitrogenous compounds, and thiocarbamates. Taste receptor cells are primarily associated with papillae on the tongue. The signal transduction mechanisms by which taste perception occurs are well not understood, but are the focus of intensive research as reviewed recently (6). 

Pebulate is a preplanting herbicide for the control of grass and broad-leaved weeds. Like the other volatile thiocarbamates, it must be incorporated in the soil. It is tolerated by a wider range of crops than EPTC. It is used in sugar beet, tomatoes and transplanted tobacco at a rate of 4-6 kg active ingredient/ha. Its action lasts for... 

CHEMISTRY AND DEVELOPMENTS OF jV-THIOCARBONYL CARBOHYDRATE DERIVATIVES SUGAR ISOTHIOCYANATES, THIOAMIDES, THIOUREAS, THIOCARBAMATES, AND THEIR CONJUGATES... 

The chemistry of sugar-derived thiocarbamic and dithiocarbamic esters was initially much less developed than that of the thiocarbamides already discussed, being limited to the condensation of reducing monosaccharides... 

The addition of alcohols to carbohydrate isothiocyanates is a general method for the preparation of linear TV-sugar, O-alkyl thiocarbamates. This reaction is frequently used as a tool for structure confirmation.34,53,54 It requires the use of a large excess of the alcohol and reflux conditions to shift the reaction to the desired thiourethane. 

Keywords Amino-oxazolines Amino-thiazolines Nucleosides Oxazolidine-2-thiones Sugar isothiocyanates Thiocarbamates... 

Various heterocycles 860 can be synthesized by the treatment of unsaturated aryl amides, carbamates, thiocarbamates and ureas 859 with IBX (Scheme 3.343) [1176,1177]. The mechanism of this reaction has been investigated in detail [1178]. On the basis of solvent effects and D-labeling studies, it was proposed that the IBX-mediated cyclization of anilides in THF involves an initial single-electron transfer (SET) to a THF-IBX complex followed by deprotonation, radical cyclization and concluding termination by hydrogen abstraction from THF [1178]. A similar IBX-mediated cyclization has been applied in the synthetic protocol for the stereoselective preparation of amino sugars [1179]. 

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