3- Deoxy-1,4-lactone

A high yield of a 3-deoxy-1,4-lactone can be obtained by hydrogenation of a peracylated aldonolactone under pressure in the presence of triethylamine.84 This... 

Synthesis from carbohydrate derived 2-deoxy lactones. Routes to C-l glycals from 2-deoxy sugar pyranolactones have been described. The general strategy is outlined in Scheme 9. 

Scheme 9 Routes to C-l glycals from 2-deoxy lactones.

Di-0-acetyl-3-deoxy-D-arabino-1,4-lactone D-threo-Pentoic acid, 3-deoxy- lactone, 2,5-diacetate (10) (79580-65-7)... 

Aldono-1,4-lactones, having six or more carbon atoms also form an exocyclic aceteoxonium ion between the primary and the neighbouring hydroxy group when treated with hydrogen bromide in acetic acid. By the opening of this ion, bromine is easily introduced at the primary carbon (Scheme 1, entry II). Pento-nolactones also yield 5-bromo-5-deoxy-lactones when treated with HBr-HOAc, although the reaction requires 1-4 days. Since no exocyclic acetoxonium ion can be formed, a direct substitution probably takes place in these cases. 

Under non-aqueous conditions the epoxy function in the epoxylactones can be opened only by Lewis acid assistance. Thus, 2-fluoro-2-deoxy-lactones have been prepared from 2,3-epoxylactones by treatment with HF-amine complexes [38,49,50], while 5,6-epoxylactones yield 6-deoxy-6-fluoro-lactones by this treatment [49, 50]. Likewise, BFj-assisted opening of a 2,3- epoxy function with TMSN3 [51] gave a 2-azido-2-deoxy-lactone [52]. In all cases the opening of the epoxide is a frans-opening, and it is noteworthy that under acidic conditions the nucleophile attacks at C-2 or at the primary position, similar to the opening of acetoxonium ions by bromide ions in the... 

We also tried to trap the presumed intermediate radical A using acrylonitrile, butyl vinyl ether or allyltributylstannane as the trapping reagents. In the first two cases mixtures of the 2-deoxy-lactone 65 and the C-2-alkylated product were obtained. Treatment of 20 with allyltributylstannane gave 68 as a homogeneous product (Scheme 14) in a fully stereocontrolled reaction [45,98b]. 

Cyclization by Displacement of Leaving Groups in Carbohydrate Substrates by Amines. The synthesis of l,2,4-trideoxy-l,4-imino-D-erythro-pentitol (31) has been achieved in eight steps, in 42% overall yield, from 2,5-di-O-p-tol-uenesulfonyl-D-ribono-1,4-lactone according to Scheme 7. The correct stereochemistry in the product was achieved by epimerization at C-4 in a 5-0-tosylated 2-deoxy lactone intermediate base action on the lactone produced a 4,5-epoxide of an open-chain carboxylate derivative which subsequently ring-closed by intramolecular attack of the carboxylate anion on the epoxide to produce the diastereomeric lactone. ... 

Scheme 9). The mixed azides (34) were also converted to the 3-deoxy-lactone (36) via a 2,3-ene. Treatment of l,2-tcaas-2-... 

Azido-3,4,6-tri-0-benzyl-D-galactose 49 was synthesized from tri-O-benzyl-D-galactal 47 by the short, efficient route shown in Scheme 7, the key step being the reaction of the anion formed from the 2-deoxy-lactone 48 with triisopropyl-phenylsulfonyl azide. 2-Azido-3,4,6-tri-0-benzyl-D-mannose was similarly obtained as the sole product from tri-6>-benzyl-D-glucal. In both cases the azide is introduced trans to the substituent at C-4. ... 

The maciocyclic lactone of all avermectins has an a-L-oleandtosyl-a-L-oleanchosyloxy substituent at carbon 13, which is a 2-deoxy sugar glycoside. 

A third, and more promising, route is currently under investigation. Bromine oxidation of an aqueous solution of 2-deoxy-D-nbo-hexose gave the hitherto unreported 2-deoxy-D-nbo-hexono-l,4-lactone, which was benzoylated to yield 3,5,6-tri-0-benzoyl-2-deoxy-D-nbo-hexono-l,4-lactone. Studies are in progress to effect a reduction of the benzoylated... 

Deoxy-D-ribo-hexono-l,4-lactone. To 286 mg. of 2-deoxy-D-ribo-hexose in 4 ml. of water is added 0.3 ml. of bromine. The solution is kept overnight at 37°C. and is then aerated to remove the excess bromine. Silver carbonate (1.5 grams) is added and the mixture is filtered. The clear filtrate is stirred with 5.4 grams of Dowex-50W X8 (H+) ion-exchange resin, decolorized, and filtered, and the filtrate is evaporated... 

Deoxy-D-nbo-hexono-1,5-lactone 5-Amino-5-deoxy-D-mannono-1,5-lactam Acyl halides are named by changing the ending -onic acid to -onoyl halide Example ... 

Deoxy-5-fluoro-D-glucose and -L-idose were synthesized from 1,2-(9-isopropylidene-a-D-glucofuranurono-6,3-lactone (285). Treatment of l,2-0-isopropylidene-5-0-triflyl-a-D-gluco- (286 prepared from 285) and -) -L-ido-furanurono-6,3-lactones (289 prepared from 288), with BU4NF... 

When 1,2-0-isopropylidene- (285) or -benzylidene-a-D-glucofuranur-ono-6,3-lactones or 1,2-0-isopropylidene- -L-idofuranurono-6,3-lactone (288) were treated with DAST, 5-deoxy-5-fluoro-6,3-lactones 287 and 290 and 3,6-anhydro-6,6-difluorofuranoses 403 and 404 were formed in good total yield [287 403 = 13 58 (71 %) 290 404 = 2 3 (75%)]. As these products did not undergo further fluorination, an OH-5-assisted mechanism was proposed. 

The effect of lactone ring-size on the inhibition was studied, for N-acetyl-)3-D-glucosaminidase from bovine epididymis, with lactones and lactone derivatives unable to undeigo ring-isomerization, by Pokomy and co-workers. From a comparison of Kj values for 2-acetamido-2-deoxy-D-glu-cono-1,5-lactone (0.45 nM) with the 1,4-lactone (4.5 fiM) and of Kj for the methyl ) -furanoside with that for the pyranose (4 mM), it was concluded that the 1,4-lactone has an 10-fold lower inhibitory potency than the 1,5-lactone. The weak inhibition by the 5,6-O-isopropylidene derivative of the... 

IC with bovine enzyme which is very similar to the human one. Inhibitor concentration for 50% inhibition. K of substrate (phenyl a-D-mannopyranoside). K of substrate (4-nitrophenyl a-D-manno-pyranoside). K of substrate (4-nitrophenyl D-glucosiduronic acid). K of substrate (4-nitrophenyl 2-acetamido-2-deoxy- o-glueoside). Inhibitors were chitotetraono-1,5-lactone and chitotetraose, respectively. 

The results of inhibition studies with aldonolactones and 5-amino-5-deoxyaldonolactams may be summarized as follows y -D-glycosidases are inhibited by 1,5-lactones and the lactams some 100- to > 10,000-fold better than by the parent aldoses, with Kj values from 200 //Mto <0.1 nM. Al-dono-1,4-lactones are probably no better inhibitors than aldoses or polyols of comparable structure, with the possible exception s of 2-acetamido-2-deoxy-D-glucono-1,4-lactone. 

Fom- title compounds, 5-deoxy KDG Me estw, 5-epi KDG Me ester, 4-0-Me KDG Me ester and 4-deoxy KDG Me ester were prepared either from D-glucono-l,5-lactone or from 1,2 5,6 di-O-isopropylidene-D-mannitol. Biological tests perfcHined rat these molecules have shown that the compounds modified on the C-5 position (5-deoxy KDG Me ester and 5-epi KDG Me ester) are gratuitous inducers of the e>q>ression of pectinase genes in the phytopathogenic bacteria Erwinia Chrysanthemi when the C-4 modified molecules (4-0-Me KDG Me ester and 4-deoxy KDG Me ester) are not inducers. 

Calcium bis(2-amino-2,3,4-trideoxy-L-gZycero-pentarate) (calcium di-L-glutamate), tetrahydrate D-Arabinono-1,4-lactone Calcium L-arabinonate, pentahydrate Strontium L-arabinonate, pentahydrate Barium D-ribose 5-phosphate, pentahydrate 2-Deoxy-D-en/thro-pentose j8-DL-Arabinopyranose... 

CI8H21Br07S 5-0-(p-Bromophenylsulfonyl)-2,21-0-cyclohexylidene-3-deoxy-2-C-(hydroxymethyl)-D-erythro-pentono-1,4-lactone HCDBPL 30 454... 

---