Mannono-1,4-lactone

Hall and Bischofberger177 found that, when 2,3 5,6-di-0-isopro-pylidene-D-gulono-1,4-lactone was oxidized with ruthenium(VIII) oxide and an excess of sodium periodate, it gave 2,3 5,6-di-0-isopro-pylidene-D-riho-4-hexulosono-l,4-[(R) or (S)]-lactol. Similar results were observed with 2,3 5,6-di-0-isopropylidene-D-mannono-1,4-lactone and 2,3 5,6-di-O-isopropylidene-D-allono-l,4-lactone. This oxidation presumably proceeds by way of lactone cleavage and oxidation of the free 4-hydroxyl group followed, on acidification by relac-tonization, and formation of the new lactol. 

Carbohydrate lactones have been used as the carbonyl reagent in the Reformatsky reaction. Thus, 2,3 5,6-di-O-cyclohexylidene-D-mannono-1,4-lactone [44, obtained by oxidation of the mannofuranose derivative (49)] reacted with ethyl bromoacetate and zinc to give the protected 2-deoxy-3-octulosonic acid ethyl ester (45a) in 69% yield (50). Ketonic hydrolysis with potassium hydroxide in aqueous methanol, followed by acidification and heating, afforded the 1-deoxyheptulose derivative 45b. Similarly, starting from compound 44, the 1-C-substituted allyl and propar-gyl lactols were prepared on reaction with allyl or propaigyl bromides in the presence of zinc (51). 

D-mannono 1,4-lactones (8b, 9a, and 10a) react readily with mesyl chloride in pyridine at 0 ° C to produce (197) the corresponding hex-2-enono-1,4-lactone 2-mesylates 150-152. 

Catalytic hydrogenation (194) of butenolide 147, obtained from D-galac-tono-, D-glucono-, or D-mannono-1,4-lactones, afforded stereoselectively the 2,6-di-0-benzoyl-3,5-dideoxy-D,L-t/ira>hexo no-1,4-lactone 177. 

Butenolides have also been prepared from aldohexono-1,4-lactones via trimethylammonium methylidene derivatives (15). 5,6-0-Isopropylidene-L-gulono- (9a) and D-mannono-1,4-lactone (10a) were converted into 2-(di-methylamino)-l,3-dioxolane derivatives, which on treatment with iodomethane followed by thermal decomposition yielded compounds 226 and 227 respectively. 

Among them are found the naturally occurring 1-deoxynojirimycin (DNJ) and 1-deoxymannojirimycin (DMJ) [96]. Practical syntheses of DNJ and DMJ start from L-gulono-1,4-lactone (20b) and o-mannono-1,4-lactone (74), respectively [97]. Key intermediates are 2,6-dibromo-2,6-dideoxy-D-alditol derivatives 75a and 75b obtained by 2,6-dibromination of the starting lactones, followed by reduction with NaBH4 [98, 99]. Then a five-step sequence involving selective partial protection, introduction of an amine functionality, and intramolecular N-alkylation, lead to DNJ and DMJ, respectively (Scheme 22). 

When the dibromodideoxy-o-mannono-1,4-lactone (2) (Scheme 7) was treated with aqueous ammonia the 3,6-dideoxy-3,6-imino-D-allonamide (22) was formed as the only product [20]. Conversion to the ethyl ester and subsequent reduction of the ester with sodium borohydride transformed 22 into the known l,4-dideoxy-l,4-imino-L-allitol (23) [20]. 

In model experiments,205 it was found that concentration of an aqueous solution of the aldonic acids in the presence of hydrochloric acid gives exclusively the 1,4-lactones, which, on subsequent trimethyl-silylation, give only one peak on the chromatogram. This method was successfully employed for the separation of D-galacturonic, D-glucuronic, and D-mannuronic acids. Of the 1,4-lactones examined, only the trimethylsilyl ether of D-mannono-1,4-lactone was obtained in crystalline form. However, all of the derivatives showed characteristic differences in their infrared spectra in the range of 1500 to 600 cm"1. When this method was applied to the determination of uronic acids in a variety of polysaccharides,205 it was impossible to find any hydrolytic conditions under which the uronic acids were quantitatively released and then reduced, a problem experienced by other workers.20 The method was, however, successful in affording a qualitative, microscale procedure for the identification of hexuronic acids (which otherwise are difficult to detect). 

In parallel fashion, compound 267, made from 2,3 5,6-di-<9-isopropyl-idene-D-mannono-1,4-lactone by Reformatsky addition using ethyl bromo-acetate and zinc-silver graphite, undergoes ready elimination when converted to the methanesulfonic ester to give a separable mixture of the E- and Z-alkenes (268).251 Quite a different approach involves treatment of the 1-C-nitromannofuranosyl chloride, derived from the oxime of 2,3 5,6-di-O-isopropylidene-D-mannose, with the anion of diethyl malonate to give the disubstituted alkene 269.252... 

These data indicate that the rate of hydrolysis of the lactones is also, to a considerable extent, affected by the stereoisomerism of the molecule. For instance, the lactones of n-mannonic acid are more stable than those of D-gluconic acid, from which they only differ in the steric position of the hydroxyl group at C2. A mixture of n-glucono-1,4-lactone and n-mannono-1,4-lactone can be fractionated by the absorption, on an anion-exchange... 

A suitable method for the preparation of L-eryf/iro-(3-hydroxyhistidine has been reported from D-glucosamine as a starting material (Scheme 1)." Thus, 2-amino-2-deoxy-D-mannono-1,4-lactone (5) was obtained from D-glucosamine in 53% overall yield." " Its... 

The only known example, 517, was prepared by condensation of the D-mannono-1,4-lactone derivative 515 and the oxazole derivative 516 [77JCS(P1)743] (Scheme 133). 

The C2-symmetric homochiral pyrrolidine 424 has been prepared in several steps from L-mannono-1,4-lactone via L-mannitoI (for the enantiomer of 424 see Vol.25, Chapter 14, ref. 108). Another interesting C2-symmetric ligand the bipyridyl compound 426 was prepared from diacetone-D-glucose through oxidation and then diastereoselective addition of 2-bromo-6-lithiopyridine to give 425 followed by nickel dichloride/Zn-catalysed coupling. ... 

O-Isopropylidene 2,3-O-Isopropyli-dene-D-mannono-1,4-lactone C9H14O6 218.206... 

O-Isopropylidene, 2-0-(trifluorometha-nesulfonyl) 5,6-0-Isopropylidene-2-triflyl-D-mannono-1,4-lactone CioHijFsOgS 350.269... 

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