Kccrystallizatioii fruiii methanol gavc iiictliyl 2,:1,4,citetra-@acetyl ~-D-glUCOpyraIlOside,n1.p. and mixed 1n.p. 104-10jo, [a]"D -22.2' in ethanol (62.7); literature values: 1n.p. 104-1054,i2 and [ C Y ] * ~ D-24.6" (ethanol),l3 -27,2" (ethanol) . 4 Deacetylatioii of thc methyl tetra-0-acetyl p-D-glucop),ranoside by the Zemplitn methodI4 using catalytic amounts of sodium methoxide gave methyl p-D-glucopyranosidc, m.p. and mixed m.p. 115-116", [ c Y ] ~ ~-30.3" D in water (c 2.0) (after recrystallization from methanol-ether); literature values: m.p. 110°,15 105'16 and IS ED -32' (13~0),15 -34.2' (H10).I6 2 . Methyl p-Lactoside.--Application of the above procedure t o acctohronio lactose yielded the corresponding methyl p-lactoside, m.p. 205', [ a ] z s ~+ l o in water (c 5.0). Inasniuch :is the pure methyl @-lactoside showed [a]25D +5.6" in \v:itcr5 it is believed that the compound above contained some of the or-anomer. B. 1. Methyl a-D-Mannopyranoside .-To crystalliiie D-matinose (18.0 g.) was added 3% hydrogen chloride in methanol (15 ml.) and ethylene dichloride (30 ml.). The mixture was refluxed on the water-bath for 4 hours. During the course of the reaction a two-phase liquid system was formed, the lower layer of which soon turned to a solid crystalline mass. After being allowed to cool, the reaction inisture was filtered and washed with a little ice-cold methanol followed by ether. The crystalline methyl a-D-mannopyranoside (yield 9.7 g.) had m.p. and mixed m.p. 191192", [ a ] % f79.0" in water (c 1.0) (after recrystallization from SO% ethanol); literature values: r11.p. 191-192"," [ a ] " D 4-79" (Hac)),'' f79.2" (HyO).'* 2. Methyl P-L-Arabopyranoside.-A mixture of 3% methanolic hydrogen chloride (70 nil.), ethylene dichloride (100 ml.) and L-arabinose (70 9.) was refluxed for 3 hours and allowed to stand overnight. The methyl p-L-arabopyranoside (yield 23.5 9.) vas filtered off and mashed with ethyl acetate and recrystallized from absolute ethanol, m.p. and mixed m.p. 166-168". [ a ] I 9 ~$2.75" in water (c 1.7); literature values: m.p. 169"19and 169-171°.20 Repeatcd recrystallization did not change the specific rotation which does not agree v i t h the literature value ( [ a*OD ] +245.5" iii wateri.1g As a further check on its purity a sainple of the material ( [ C U ] D $235') was oxidized with periodic acid according to the procedure of Hudson arid Jackson .21 The D'-met~lOx\-digl~~COliC aldehyde obtained had [ G ] * ~ D t 1 2 3 ' (T-120); Hudson arid Jacksonz1 reported [a]zn +124' ~ (HyO) for this substance. g.).
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( J 2 ) J. RIoll v a n C h n r a n t e , RFC.f r i i v . c h i i n , 2 1 , 42 (1902). nd J. K. D a l e , THISJOURNAL. 57, 1264 (191.iJ. Y . , 69, 1258 (1926); G . Zemplkn a n d E . P a c s u ,
bility relationships between tlic rcactaiits arid the alcoholic solvent were such t h a t the alkali-sensitivc sugars dissolved and the resulting salts of the nitrodeoxyalditols precipitated as the condensation rcaction progressed. While many of the aldose sugars condense satisfactorily with nitroinethane in alkaline alcoholic media, others such as D-glucose react to only a mitior e ~ t e n t . ~ m'ith a view t o increasing the scope and utility oT the nitroparaflin~-sugarcondensation, the reactioii now is being studied in uqueous solution. The condensation of D-arabinose with nitromethalie j i I aqueous alkali has been fouiid to proceed rapidly and to an extent comparable with t h a t observed in alcoholic media. It seems likely t h a t the use of aqueous reactioii conditions will appreciably extend the applicability of the nitroinethane and related syitheses iri thc sugar field. Further experiments arc coiitcn~platctl to generalize the above results. Experimental Solutiolis coiitaiiiiiig n-arabinose iii 2 equivalctits of 2 .I/ nitromethane in 2 A T aqueous sodium hydroxide were allowed to stand a t room temperature for \-arying lengths of tirnr and the resulting nci-nitroalcohols then were decomposed by adding the solutions to xrarm ( S O ' ) , aqueous sulfuric acid.' Following deionization and concentration, D-mannose was precipitated from the resulting solutions as the phenylhydrazcne. The rela tionship between the duration of the condensatiou reaction and the yield of D-mannosc phenylhydrazone was as folloxs: 6 min., 15.4yo;15 min., 20.6%; 25 min., 21.6%; 1 hr., 18.4%; 2 hr., 17.5%. \Vhen the amount of the alkaline riitrornethane solution was varied, a condensation reaction time of 15 iniiiutes resulted in the following yields of D-mannose phenylhydrazone: 1 cqui\-., 16.9%; 2 equiv., 20.670; 3 equiv., 17.6%. D-Mannose phenylhydrazonc was characterized h y coliversion to thc known a n h y d r o - 0 - t ~ t r a a c e t a t e ,~11.1). ~ 123I%', [ u ] * ~ D12' i t i pyridine ( c 3 ) . .
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U E P A R ~ MI Eoi: S CIIK~IISI.RY WASHINGI-OS USIVERSIYY
SAINT LOVIS,~ I I S S O U R I ( 1 5 ) T. S P a t t e r s o n a n d J. R o b e r t s o n , .I. Cherii. Soc., 300 (19291. 1 1 0 ) C. N. R i i h e r , Ber., 67, 1707 (19241. (17) 51. B e r g m a n n a n d H. S c h o t t e , i b i d . , 6 4 , 1569 (11121). (18) Is. Fischer a n d L. Beensch, i b i d . , 29, 2928 (1896). (19) C. S. H u d s o n , TIiIs J O U R N A L , 47, 267 (1925). Fischer, Rev., 2 6 , 2107 (1893). I,. Jackson a n d C. S. Hudson, THISJ O U R N A L , 69, 994
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