2,3-O-ISOPROPYLIDENE-L-ERYTHROTETRURONIC ACID AND -L-ERYTHROSE, AND THE METHYLD-ERYTHRO- ANDD-THREO-TETROFURANOSIDES

Abstract

Oxidation of 2,3-0-isopropylidene-8-L-rhamnose (I) with hypoiodite, follo\ved by periodate cleavage of the derived aIdonic acid, affords 2,3-0-isopropylidene-L-ery~huotetruroiii acid.Reduction of I with sodium borohydride and periodate oxidation of the resulting glycitol gives 2,3-0-isopropylidene-L-erythrose. Both products have been obtained in high yield, and are readily hydroIyzed to L-erythrotetruronic acid and L-erythrose, respectively.Methyl a-and 8-D-erythro-and D-threo-tetrofuranosides have been prepared by the Fischer glycoside synthesis from D-erythrose-and D-threose-formates, respectively. A notable anomeric difference in the lead tetraacetate oxidation behavior of the methyl D-threosides has been observed, the 0-anomer being more reactive than the a-anomer.111 continuing earlier studies in this laboratory on the chenlistry of the tetrose sugars (1, 2, 3, 4) several new tetrose derivatives have been prepared and are described in the current paper.Stepwise degradation of D-glucuronic and D-galacturonic acids t o D-erythro-and D-threo-tetruronic acids, respectively, by lead tetraacetate oxidation has been described previously (3). Since the L-isomers of these hexuronic acids are rare compounds, they do not provide practical sources of the L-tetruronic acids. The L-threo-isomer has been prepared by selective reduction of 2,3-di-0-acetyl-L-tartaric anhydride ( 5 ) and by oxidative degradation of D-glucosaccharo-7-lactone (6), but the L-erythro-acid does not appear to have been reported. I n the current paper a inethocl is described for preparing L-erythrotetruronic acid from readily available 2,3-0-isopropylidene-~-rl~a1~~nose (7) (I).The latter derivative also has been utilized to prepare L-erythrose in high yield.Xcetonatio~l of L-rhamnose in the presence of hydrogen chloride (7) appears to yield the 2,3-0-isopropylidene derivative allnost exclusively. Two crystalline forms of monoacetone L-rhamnose have been described (8,9) but only the p-anomer (9) has been isolated in the present study. The isopropylidene derivative (I) was oxidized with hypoiodite (10) t o the L-rhamnonate (11) and the latter, which was not isolated, \\-as degraded by perioclate cleavage. From the reaction misture crystalline 2,3-0-isopropylidene-L-erythrotetruronic acid (111) was isolated in about 75% yield. Chromatographically pure L-erythrotetruronic acid was readily obtained by autohydrolysis of 111 in aqueous solution.Reduction of isopi-opylidene-P-L-rhamnose (I) to the rhamnitol derivative (IV), followed by periodate oxidation, afforded crystalline 2,3-0-isopropylidene-L-erythrose (V) in about 80% yield. The L-glycitol derivative (IV) was obtained as a syrup by catalytic hydrogenation but, \\-it11 socliunl borohydride reduction, attempts to isolate it resulted in partial hydrolysis of the isopropylidelle group. For preparation of V, however, it was most convenient to carry out the reduction \\lit11 borohydride and, after neutralizing the reaction mixture, to continue directly \\-it11 the periodate cleavage step. Such a...

2,3-O-isopropylidene-alpha-D-lyxofuranose, monoacetone-D-lyxose of Levene and Tipson

“…These two carbon atoms become C–3

and C–2, respectively, of the derived tetrose, but, due to the symmetry of the substituent, compounds I through VII are all 2,3- O -isopropylidene derivatives. Of these, compounds IV and V had previously been prepared but not crystallized [ 11 ], and the enantiomorph of V was recently crystallized by Baxter and Perlin [ 12 ].…”

SPECTROPHOTOMETRIC OBSERVATIONS ON THE CLEAVAGE OF vic-DIOLS BY LEAD TETRAACETATE

“…One advantage gained in this way is t h a t reaction rates for very fast glycols (such as those in which the dihedral angle of the carbon-oxygen bonds approsinlates 0 degree (3,4)) are slowed sufficiently3 for satisfactory measurement, particularly with a recording spectrophotometer. T o illustrate, the rate of cleavage of the 2,3-cis diol of methyl a-or p-D-erythrofuranoside mas found earlier (5) to be virtually instantaneous even a t O0 C, so that comparative data were not available. However, the rate for each conlpound a t high dilution has now been estimated readily, and a substantial ano~neric difference detected.…”

C-Nucleosides and related compounds. VI. Carbocyclic analogues of C-nucleosides: synthesis and derivatives of some useful intermediates

“…The low field spectrunl indicated that the free aldehyde was present to the extent of only 30%. In solution, the free aldehyde 5 is in equilibrium with its bridged hydrated form (14,15). Treatment of 5 in dimethyl formamide with 2 molar equiv.…”

“…We attempted to improve the yield of this reduced at low temperature with dimethyl reaction using catalytic osmylation (4) with sulfide according to the procedure of Pappas osmium tetroxide and hydrogen peroxide but et al (13). The resulting dialdehyde 15 existed the yield did not exceed 30%.…”

“…mainly in its bridged hydrated form (14,15) as a Treatment of the diol 18 with acetone, 2,2-mixture ofseveral isomers and wascharacterized dimethoxypropane, and a trace of p-toluene-by its bis-thiosemicarbazone 150, mp 168 "C sulfonic acid afforded the isopropylidene deriva-(dec. For personal use only. the corresponding diol14.…”