Fructose D-, derivatives

From a structural point view, the most explored thionocarbamates in carbohydrate chemistry are five-membered l,3-oxazolidine-2-thiones.27 29 With respect to the synthesis of aromatic analogues of OZTs-1,3 oxazoline-2-thiones (OXTs), only two acyclic D-fructose-derived OXTs were recently reported by Rollin and co-workers.30... 

A 3-0-benzylated D-fructose derivative was produced from l,2 4,5-di-O-isopropylidene-P-D-fructopyranose under standard conditions (Scheme 26). Transient 3-0-benzylated D-fructose resulting from acidic hydrolysis was reacted with thiocyanic acid without intermediate purification. This sequence afforded a mixture of isomeric spiro-OZT on pyran and furan templates, which was difficult to separate, even if standard acetylation was applied. 

The D-fructose-derived, chiral, nonracemic l,3-oxazin-2-one derivative 260 exerted smooth stereocontrol, resulting in high levels of asymmetric induction and good chemical yields in various synthetic transformations. The chiral fragments 256 and 261 formed in the aldol or a-bromination reactions of the A -propionyl derivative 257 could easily be removed from the parent auxiliary by mild hydrolysis (Scheme 48). The Diels-Alder cyloadditions of the A -acryloyl and A -cinnamoyl derivatives of 260 were also characterized by excellent diasterofacial selectivity <1998T9765>. 

Table IV, which briefly summarizes the material described in previous sub-sections, shows the total of the different monosaccharide components identified in bacterial polysaccharides, and our present knowledge about their activated forms. It may be seen that identification of the activated forms has been achieved for only approximately half of the monosaccharides known to be involved. The most striking gap in the information available is the lack of data about the activated forms of D-ribose-derived monosaccharides and of most of the D-fructose-derived aldoses having configurations other than gluco, galacto, and manno.

Even forcing conditions did not cause the anhydro-D-fructose derivative 53 to undergo photochlorination with iV-chlorosuccinimide, but, with sul-furyl chloride-azobis(isobutanonitrile) in refluxing carbon tetrachloride, it gave several products, one of the major being the crystalline a-chloro analog of the bromide 56 (14% isolated).50... 

Whereas the chiral TEMPO analog 87 was used to resolve racemic secondary alcohols, the D-fructose-derived ketone 88 [137] proved useful for oxidative resolution of racemic diols (Table 10.13) [138, 139], Persulfate in the form of Oxone, Curox, etc., served as the final oxidizing agent, and the dioxirane generated from the ketone 88 is the chiral active species. Because of the relatively low conversions (except for unsubstituted dihydrobenzoin) at which the ee stated were achieved, the method currently seems to be of less practical value. Furthermore, typically 3 equiv. ketone 88 had to be employed [138, 139]. 

The 3-D-Fructofuranose Site. In the gerbil MBFF (methyl B-D-fructofuranoside) as well as sucrose (a-g-glucopyranosyl - B-D-fructofuranoside)was the most stimulatory D-fructose derivatives tested. This finding suggests the presence of a specific fructose site. This is not unlike the fly s g-fructose site (23) which responds best to B-D-fructofuranose (24). ... 

In the sorbose series 3-methyl-D-sorbo8e14 has been synthesized, as well as the aforementioned 4-methyl-8 derivative the latter compound was obtained in a series of reactions from D-fructose derivatives through l,2-isopropylidene-3,4-anhydro-D-psicose. In the earlier study8 the configuration of the 4-methyl ketohexose was shown to be that of a D-sorbopyranose by methylation of l,2-isopropylidene-4-methyl-D-sorbose (VI) to the trimethyl derivative (LXV) which was hydrolyzed to 3,4,5-trimethyl-D-sorbose (LXVI). The latter compound, on oxidation, gave derivatives of levorotatory dimethoxysuccinic acid (LXVIII) and xylo-trimethoxyglutaric acid (LXVII). 

ASYMMETRIC EPOXIDATION OF trans-p-METHYLSTYRENE AND 1-PHENYLCYCLOHEXENE USING A D-FRUCTOSE-DERIVED KETONE (R,R)-trans-P-METHYLSTYRENE OXIDE AND (R,R)-l-PHENYLCYCLOHEXENE OXIDE... 

D-fructose-derived compounds as efficient chiral ligands for stereoselective carbon-carbon bond-forming reactions [174,175,176,177,178,179]. The remarkable results found by the Zheng/Chen group are summarized below. 

R " = H, alkyl, aryl, substituted alkyl and aryl SIRs = SIMes, SiMe2(t-Bu), SIEts solvent CHoCH. pentane, toluene n = 1-3 chiral oxidant Davis chiral oxaziridine, Shi s D-fructose derived ketone/Oxone, (Salen)manganese(lll)-complexes/NaOCI or PhIO... 

Mossine, V. V., Glinsky, G. V., and Eeather, M. S. (1994). The preparation and characterization of some Amadori compounds (1-aniino-l-deoxy-D-fructose derivatives) derived from a series of aliphatic amino acids. Carbohydr. Res. 262, 257-270. 

---