M. L. WOLFROM AND ROBERT L. BROWN
1516
combined (49 mg.) and recrystallized several times from methanol. The pure compound, tentatively assigned structure 1-111,formed rosets of elongated platelets melting d t 218-219" (dec 1 , [ a J z l u7 143 3' (2 G i ' , l b 6 mg. in 2 cc.. 2 dni ). The absorption curbe showed a well defined iingle maximum at 254 r w , B 10,400 (in ethanol I
The compound failcd t o react with 2.1-dinitrophenylhydrazine under the usual conditio~i~ '
We are greatly indebted to Dr. S.11. Coy of the Vitamin Laboratorv of € < ~ R. Squibh atid Sons (6) T h e fact t h a t compounds VI, VI1 and VI11 which undoubtedly are ketones could not be derivatized with 2,4-dinitrophenylhydrazine must be ascribed t o steric factors, t h a t is, most probably to t h e presence of interfering groups in positions 8 and 14, However, it must be admitted t h a t this explanation does nor account for t h e failure of 3,^ ~)-acetoxy-_?i--l'-ergostenediocc-5,iS tu yield a dinitrophenylhydrazone, although thii compound readily rezcr- rvitli hyd;-.azine t o f o r m *: pyrirlaiine rleri?;li. r' .
ILL)\
%
t R I 1 3 L I l U \ I XO\f
I I l t CHPVIc.iI
Vol. 65
for the spectrographic measurements. The microanalyses were carried out by Mr. J. F. dlicino of this Laboratory.
Summary Mild oxidation of a ( L?.8-i4)-cholestenylacetate with chromic acid results in the formation of a number of ketonic compounds. Both methylene groups in a-position to the 8,li-double bond are attacked. The double bond itself either remains unchanged, or adds oxygen in form of an epoxide group or of tertiary hydroxyl groups. The compound formed in largest amount is the ^i-keto-s,l4-oxide previously obtained via the corresponding 7-hydroxy compound from y ( 4718) cholestenyl acetate. N F WBRT:SSTVICK, N. J .
RECEIVED MARCH 27, 1943
L A B O R A l O K Y OF 'rH6 O H I O b T A l € I T S I V t R S I T Y ]
The Action of Diazomethane upon Acyclic Sugar Derivatives. V.' tives
Halogen Deriva-
TABLEI The conversion d' ;1 diazomethyl to J. chloroCOMPARATIVE RO'TATORY I'OIVERS O F 1-HaLo-kecoor bromomethyl group with halogen hydride was ACETATES established by Curtius.' buch conversions have [ .] :1--28D M. p., abs. been effected4 with l-diazo-l-desoxy-keto-n-frucSubstance CHCls [M] tose tetraacetate and 1-diazo-]-desoxy-keto-n- 1~Cliloro-ketcJ-D-fructosr tetaacetateJ 77.5-78 +68' +24,900 glucoheptulose pentaacetate. In the present work, the optical rotations of these previously re- 1-Hromo-keto-D-fructose t etraacetate 67-68 +26,8OO ported halogen clerivatir es l i e ~been ~ renieasured J otio-keto-n frui I ow and new values established 111 several cases. .itj-;i6 1 etraacetate +28,900 !-ll)iazo-l-rlesoxy-keto-rJ-gslaheptult)s~ pentaaceChloro-keio-D-glucotatel (I) has now been converted to the 1-chloro licptulose pentaacetate 1 00 101 - 1,200 Iirorno-keto-D-glucohep~ n r t 1-bromo derivatives 111 the same iniiiiiier - Z,70CI tulo\e pt ritaacetate 87-88 The 1-chloro compound exhibited dimorphism. 79-81" - 5,200 I odo keto- u-glucohept 11 The 1-iodo derivati\ e i iii thest thrw sugar lost. pentaacetatc 89-90" itructures were then obtained lrom the chloroCbloro-keto-D-galahepcompounds by halogen interchange' with sodium ulwe pentaacetate 101 -102" - 14,500 iodide in l(ronio-keto-u-galaheptu124-125 - 17,400 lose pentaacetate The measured physical constarits obtained for -1odo-keto-D-galaheptuthe three I-halo-derivatives each of these 144-1 46 lose pentaacetate - 33,900 < i cetylated keto-sugar structures are tabulated in O C .
1
( i f
' Ihrnorphir
(1) Previous publication in this series M I, Wolfrom, R Brown and E F E % ~ LrCm s J u I x ' r h ~66 1 0 1 , 1 0 1 1 2 , D L Poat Feliov, 1941-1942 (3, (a) T Curtiui Neo 16,75-1,223(1'18 12J 38, 396 (1988) 14) Lf L Wolfram, b \\ \ j O U R N A L , 64, 1701 (1942) ( 5 ) W H. Perkin aud H F Duppa A n i ' , 112, 1 2 5 1 van Romburgb, Rec t i a t chrm t 1 rl T inkrl.tr?i. r i 1 43 I
I
Table 1. The melting points show a decrease in the sequence C1+ Br -+ I for the D-fructose and D-glucoheptulose (D-gluco-D-sorbo-heptose)structures but exhibit an increase for D-galaheptulose In-gala-L-fructo-heptose). The trend of molecular ri it,itinii wquence i c reversed iri the D-fructose
Duzom~~i.uwi ON ACYCLIC HALOGENSUGARDERIVATIVES
Aug., 1943
series when compared to the D-gala-L-fructoheptose (wgalaheptulose) compounds, in accordance with the enantiomorphic fructose structures present. The interchange of halogen on carbon one has a relatively small &ect on the rotatory power. An even smaller effect in rotation between the bromo and iodo derivatives on carbon six of an acyclic sugar structure has been reported' for 6-bromo-D-glucose diethyl mercaptal tetrabenzoate (spec. rot. +39' in CHCb at 25" and D line; [MI +30,000) and 6-iodo-D-glucose diethyl mercaptal tetrabenzoate (spec. rot. +39O in CHCls at 27' and D line; [MI +32,000). These &e& are in contrast to the large differences in rotation observable on halogen interchange when the halogen is attached to the carbonyl carbon of aldoses in their cyclic or acyclic* forms. It is of interest to note the comparative rotatory powers of 1-dOrO-ketO-D-fNCtOSe tetraacetate (spec. rot. + 6 8 O in CHC4 at 22' and D line; [MI +24,900) and 6-cbloro-kefu-~fructose tetraacetates (spec. rot. +45O in CHCb a t 20' and D line; [MI+16,soO). Curt.iussb has shown that the diazomethyl group reacts with organic acids to form esters. This has been applied'O to the synthesis of ketoacetates through the reaction of acetic acid with the diazomethyl ketones of the acetylated sugars. In the present work we report the synthesis of the 1-(0-pentaacetyl-D-galactonate)(IV), 1-(0pentaacetyl-n-gluconate) and 1-(0-tetraacetylD-arabonate) of keto-D-galaheptulose pentaace-
1517
tate. These compounds were obtained on reaction of the diazomethyl ketone I with the corresponding fully acetylated sugar acid in benzene solution. Curtius" had demonstrated that the diazomethyl group reacted readily with iodine to form a diiodomethyl group. This reaction was attempted with l-diazo-l-desoxy-keto-o-galaheptulose pentaacetate (I) without success until it was noted that irradiation promoted the reaction. Prolonged irradiation produced decomposition. The 1.1-diiodo-keto-D-galaheptulose pentaacetate (V) so formed is a very interesting substance and should lead to the synthesis of other sugar derivatives of significance. It was found that treatment of the diazomethyl ketone I with the proper concentration of hydriodic acid led to the reduction of carbon one to yield 1-desoxy-kelo-D-galaheptulosepentaacetate, (VI). S i m i l a r treatment of the 1-iodo (111) and 1,l-diiodo (V) derivatives led to the production of the same compound. VI was isolated in dimorphic forms melting a t 65.567.5' and 7&79' and showing like rotation in solution. That these forms were homogeneous dimorphs is clearly shown by the comparative X-ray diffraction powder diagrams'* of Fig. 1and the measurements on these tabulated in Table 11. VI gave a positive iodoform test and formed an oxime.
CHtCl
I
CHzOAc
I
CHlOAc I1
I 1
CH,OAc
I
{HI CHsOCO(CHOAc), CHI.
I
C=O I
LH*OAc
I
7
(7) M.L. Wolfrom and C. C. Christ-. (1935).
HI
1"'
CH*
Similar hydriodic acid reduction of 1-diazo-1-de-
C=O
soxy-keto-D-fructose tetraacetate' led to the formation of 1-desoxy-keto-o-fructose tetraacetate, previously synthesizedla by the action of diazomethane upon aldehydo-D-arabinose tetraacetate. The reduction of ethyl diazoacetate to ethyl
I I
Tnrs J0uw.a.8V. 713
(8) M.L. Wollrom and R. L. Hm-. ibid.. 50, 951 (1943). ( 9 ) D. € Bcauns, I . ibid.. U . 1846 (1920); E. Pncsu nod P. V. Rich. a d . . M. 8018 (1933). (10) M. L. Wolfrom. S. W. Wnirbrot sod R. L. Brom. i e d . , 54. 2329 (1942).
Pig. 1.-Comparative X-ray imwdcr rliagrains of the dimorphic forms (upper, m. p. l i 5 . 5 4 i . S " ; lower, m. I). 78-79') of 1-desoxy-kclo-o-galaheptulose pentaaretate (cJ ref. 12 and Table 11).
T.Curtius. Be,.. 15, 1 2 s (1885). (12) Fm the X-ray photopaphi and messuremeolr we are indebted to Dr. F. R Senti of the EastRegional laboratory, United Statu Depnrfment of k i e u l t u r e , Pbileddphia. Peooryl".nia. (13) M. L. Wolfrom, D. 1. Weishlat, W. H. Zophy sod S. W. Wninhrot, TRIO JOURNAL. 68. 201 (1941). (11)
M. I,. WOLFROM AND ROBERTL. BROWN
1518
Vol. 65
acetate with zinc and acetic acid has been de- ether and was insoluble in petroleum ether and water. scribed by Curtius."" -4n indirect reduction of The compound reduced hot Fehling solution but gave no diazoacetophenorie through the following reaction precipitate upon boiling with alcoholic silver nitrate. A n d . Calcd. for C,HaO&l(CHaCO)s: C, 16.53; H, sequence has been rioted by U'olff.I4 CGHb- 5.28; C1, 8.08; saponification value (6 equiv.), 13.67 cc. COCHK~ c.r-15cocH----N - - SH? c6:i6- 0.1 .\- S a O H per 100 mg. Found: C, 46.23; H, 5 . 3 7 ; C1, 8.08; saponification value, 13.62 cc. EaOH COCH(I\")2 C&15COCH3. In the presI-Chloro-keto-n-glucoheptdose pentaacetate4 was purient work we describe the direct reduction of diazo- fied by ether crystallization, m. p. 100-101", spec. rot. acetophenone with hydriodic acid to yield aceto- -2.8' (ZX', c 3 ) . These constants differ slightly in the phenone. Since diazoacetophenone is conveniently rotatory value from those previously recorded": 111. p. 10[)--101', spec. rot. -5.;' (22", c 5). synthesized from benzoic acid through the reac1-Bromo-keto-D-galaheptulose Pentaacetate.-1-Diazotion of diazomethane with benzoyl chloride, l5 the I-desoxy-kefo-D-galaheptulose pentaacetate (3.0 g.) was above reduction can be foriiially considered, in treated as described above for the synthesis of l-chlororespect to the organic acid, as t i reversal of the kelo-D-galalieptulose pentaacetate except that hydrogen lxoniide was substituted for the hydrogen chloride; yield haloform reaction. 2.95 g., in. p. 122-~123". Shaking the crystals with a small All substances lierein described were obtained amount of ether removed most of the color. Pure mairi crystalline form and purified to constant rota- terial was obtained after t ~ crystallizations o from acption and melting point. tone-ether by the addition of petroleum ether; m .11. 12.4 Extension of this work is in progress in this I%", spec. rot -36" (%", c 5.3). The bromo derivative was somewhat less soluble in all Laboratory. solvents than the corresponding chloro compound. It reExperimental duced hot Fehling solution hut gave no precipitate upoii
--
--
---+
I-Chloro-keto-D-galaheptdose Pentaacetate (11).-1Diazo-l-desoxy-kcio-~-galaheptulose pentaacetate' (2.0 g.) was suspended in 30 cc. of acetonedry ether (1: 15) and treated with a sircam of dry hydrogen chloride until cessation of nitrogen evolution (five to ten minutes). T o the solution was added a small amount of decolorizing carbon and the suspension warmed a few minutes, filtered arid concentrated to a volume of 20 cc., whereupon crystallization was initiated by the addition of petroleum ether ) airti cooling; yield 1.9 g , Til. 1,. W-I02', -pet. rot. -33' (26", c 2.5).i6 Recrystallization of the above material from seven parts of ether yielded massive prisms of specific rotation -32.8" (24", 6 2.7) which softened at 89' and melted zharply a t 101'. The addition of 25 cc. of petroleum ether 70 the recrystallization mother liquors, followed by cooling, resulted in the formation of rosets of flat, fan-shaped crystals of specific rotation -32.5" (28", c 4.7) which riieitec! a t 89--!)0', t h e iiiclt, liorvever, reiiiainirig slightly c,loudy up to 102' ai which temperature it became clear. Further crystallizations of these two modifications failed t o alter their constanw. All attempts to obtain one of the iwo forms completcly iincontaminateri l v i i h the other w r e fruitless, aithough eirhcr cornporie~it could bc obiained a t will as the prcdomiiiaiit component of the mixture. 'lhus i t would appear that l-chloro-keto-n-galalreptulosc pentaacetate formed two dimorphic inodificatioris (in, p . 8!4--90" arid iOI-lV2') which were of such a i,haracttr that t h e y cwuld not readily be completely sepae substance (in either modification) was soluble i i i acetone, chloroform and benzene, moderately soluble in
(le) I.. WoltT, Arrn., 394, 23 (1912). (15) (a) E'. Arndt and J. Amende, Ber., 61, 1122 (1928); (b) W Bradley and R . Robinson, .I. Chcm. Soc., 1310 (1928). :I61 Unless otherwise noted, all rotations were taken in absolute L.hloroform solution and aL t h e D line of sodium light; 26" is the t r m p e i a t i i r r . r ~ C Ithe concentration in g . subs. per 100-cc. soln
boiling with alcoholic silver nitrate. Anal Calcd. for C7HsOsBr(CHaC0)5: C, 42.25; H, 4.79; Ur, 16.53; saponification value (6 equiv.), 18.41 cc. NaOH per 100 tng. Found: C, 41.92, 1-1, 3.05; 0.1 Rr, 16.Ci-l; saponification value, 12.46 cc. 1-Bromo-keto-D-fructose tetraacetate4 was purified1' by ether crystallization: ni. p. 6 7 4 8 " , spec. rot. +Go(21 c 3 ) ; constants previously reported4: m. p. 68", spec. rot. +f52.5' (26 O, c 4). I-Bromo-keto-D-glucoheptulose pentaacetate' was purified by ether crystallization: m. p 87.Ha",spec. rot. -5.5" i2X', c 5 ) ; constants previously reportedi: n:. p. 86-87", spec. rot. --4.0° (%&', c 5 ) . 1-Iodo-keto-D-galaheptdose Pentaacetate (lII).--To a solutio11 of 1-chloro-kelo-D-galaheptulose pentaacetate (4.0 g., 1 mole) in 50 cc. of acet.one was added a solution of sodium iodide (4.1 g., :3 moles) in 2[1 cc. of acetone. 'The solution assumed a brown color and there result.ed a s l o ~ precipitation of very finely divided sodium chloride which was removed by centrifugation and washed with acetone. The residue obtained on solvent removal \vas dissolved in chloroform and washed successively with dilute aqueou? sodium thiosulfate and water. A crystalline product was o1,tained on solvent removal from the dried chloroform solution; yield 4.5 g. (93';;) of a very light yellow crystalline product, m. p. 139-143', spec. rot. -42'. Washed with warm ether to remove the color, the product vras recrystallized by solution in a minimuin of warm acetone followed by the addit.ion of ether to yield pure 1 -iotio-kata-i~ galaheptulose pentaacetatc; i n , 1). I - & - 1 4 f i -, i p c . :rot -44.8'@6', c 3.2j. The substance crystallized a5 white, hcsagonal, iridei cent leaflets. I t was much less soluble in all solvents than the corresponding chloro and bromo analogs. In contrast to the chloro and bromo compounds the iodo-ketose gave a precipitate when boiled with alcoholic silver nitrate. It reduced.. warm Fehling solution readily. ' \ . A
O,
!!7 ) flxperimental work by Mr. R r a n I' Evans of this Laboratory.
Aug., 1943
DIAZOMETHANE ON ACYCLIC HALOGEN SUGAR DERIVATIVES
1519
Axel. Calcd. for C11H230111: C, 38.50; H , 4.37; I, cooling to 0 '. Three additional crystallizations from fifty parts of absolute ethanol yielded the pure ketose ester; 23.93; saponification value (6 equiv.), 11.31 cc. 0.1 N NaOH per 100 mg. Found: C, 38.70; H , 4.48; I, 24.09; spec. rot. +13.0° (31", c 4.8), melting points taken simultaneously in soft glass and Pyrex were 165-167 O and 171.5saponification value, 11.39 cc. 1-Iodo-keto-D-glucoheptdose Pentaacetate.-This sub- 172.5", respectively. The melt in the soft glass capillary stance was synthesized from 1-chloro-keto-D-glucoheptulose became discolored while that in Pyrex did not and, upon pentaacetate? (3.8 g.) according to the procedure de- cooling, the melt in the latter crystallized whereas that in scribed above for the corresponding galaheptulose deriva- the former did not. Anal. Calcd. for Cs3H5rOz3: C, 49.01; H , 5.48; saponitive; yield 4.4 g., m. p. 74-79", spec. rot. -9.2". The substance was recrystallized from ten parts of warm ether fication value (11 equiv.), 13.60 cc. 0.1 N NaOH per 100 by the addition of an equal volume of petroleum ether and mg. Found: C, 49.18; H, 5.54; saponification value, cooling to yield pure 1-iodo-keto-D-glucoheptulosepenta- 13.68 cc. acetate; m p 79-81', spec. rot. -9.9" (25", c 4.3). keto-D-Galaheptulose Pentaacetate 1-(0-Pentaacetyl-DThe substance crystallized as white, elongated prisms. gluconate) .-1-Diazo-1-desoxy-keto-D-galaheptulose pentaI t was less soluble in the common solvents than the corre- acetate (4.0 g., 1 mole) and D-gluconic acid pentaacetateIg sponding chloro and bromo derivatives but decidedly more (7.6 g., 2 moles) reacted in the same manner as described soluble than its galaheptulose analog. In contrast to the above for the synthesis of the corresponding 1-(0-penta1-chloro- and 1-bromoglucoheptulose derivatives4 this acetyl-D-galactonate) ester. The dry chloroform extract substance gave a precipitate when boiled with alcoholic was evaporated to a thick sirup which was dissolved in 15 silver nitrate. It readily reduced warm Fehling solution. cc. of warm ether, whereupon crystallization was initiated. Anal. Calcd. for C17H23011I: C, 38.50; H, 4.37; I, Petroleum ether was added portionwise until crystallization was complete; yield 4.8 g., m. p. 80-105", spec. rot. 23.93: saponification value (6 equiv.), 11.31 cc. 0.1 A' 19.5". The product was recrystallized (decolorizing NaOH per 100 mg. Found: C, 38.75; H, 4.36; I, 23.75; carbon) four times from twelve parts of absolute ethanol saponification value, 11.34 cc. 1-Iodo-keto-D-ftuctose Tetraacetate."-This substance to yield the pure ketose ester; m. p. 112-113", spec. was synthesized from 1-chloro-keto-D-fructosetetra- rot. +22.0" (30", c 6.1). The compound was three to four acetate4 (1.4 9.) according to the procedure described times more soluble in the common solvents than the correabove for the corresponding galaheptulose derivative. sponding galactonate derivative. Anal. Calcd. for Cs3HtrOzs: C, 49.01; €1, 5.48; saponiThe product was crystallized from alcohol by the addition of water; yield 1.5 g., m. p. 53-56". Pure material was fication value (11 equiv.), 13.60 cc. 0.1 N NaOH per 100 obtained on further crystallization performed in the same mg. Found: C, 49.15; H , 5.36; saponification value, 13.70 cc. manner; m. p. 55-56", spec. rot. +63" (21.5', c 3). The substance was soluble in acetone, chloroform and keto-D-Gdaheptulose Pentaacetate l-(O-Tetraacetyl-Dwarm alcohol, moderately so in ether and was practically arabonate).-A solution of 1-diazo-1-desoxy-keto-D-galainsoluble in petroleum ether and water. The compound heptulose pentaacetate (4.0 g., 1 mole) and D-arabonic acid formed a precipitate on heating with alcoholic silver ni- tetraacetateZ0(6.2 g., 2 moles) in 100 cc. of benzene was trate. heated under reflux for three hours and subsequently Anal. Calcd. for ClaHleOsI: C, 36.69; H, 4.18; I, treated as in the preparation of the corresponding 1-(Opentaacetyl-D-galactonate)derivative; yield 4.3 g., ni. p. 27.70. Found: C, 37.00; H , 4.22; I, 27.91. 128-139", spec. rot. +28". Four cry tallizations from keto+-Galaheptulose Pentaacetate 1-(0-Pentaacetyl-Dforty parts of absolute ethanol yielded p$.:rematerial; m. p. galactonate) (IV).-A solution of 1-diazo-l-desoxy-keto-D165.Eh56.5" (Pyrex glasi), 153-155" isoft glas;), spec. galaheptulose pentaacetate (2.0 g., 1 mole) and D-galacrot. +22.6" (32", c 5.9). tonic acid p e n t a a ~ e t a t e '(3.8 ~ g., 2 moles) in 50 cc. of benThe substance crystallized as white, very thin, elongated zene was heated under reflux for three hours. The benrectangular ledets. I t was somewhat more soluble in the zene was removed under reduced pressure and the residual common solvents than the corresponding galactonate sirup dissolved in 60 cc. of chloroform (the excess acid was derivative. more readily removed from a chloroform solution than from Anal. Calcd. for CaoH~oOpl:C, 48.91; H, 5.47; saponia benzene solution). The unreacted galactonic acid was washed from the solution with several portions of aqueous fication value (10 equiv.), 13.58 cc. 0.1 N NaOH per 100 sodium bicarbonate and the chloroform extract was mg. Found: C, 49.10; H, 5.53; saponification value, washed with water, dried and concentrated t o 10 cc. Pe- 13.54 cc. troleum ether (b. p. 3 0 4 0 " ) was added slowly to opales1,l-Diiodo-keto-D-galaheptulose Pentaacetate (V) .-A cence whereupon the substance precipitated as a light yel- quantity of 2.02 g. (1 mole) of 1-diazo-l-desoxy-keto-Dlow crystalline powder. Portionwise addition of petro- galaheptulose pentaacetate was suspended in 15 cc. of leum ether was continued until there was no further pre- absolute ethanol and 30 cc. (1.2 moles) of a solution of cipitation; yield 2.4 g., m. p. 165-170°, spec. rot. +16.5". iodine (0.38 N ) in absolute ethanol was added slowly in Recrystallization was effected by solution of the crude ma- small portions while the mixture was irradiated a t a disterial in 50 parts of hot ethanol (957,) followed by the tance of about one inch from a No. 1 photoflood bulb. addition of warm water to incipient crystallization and The solution was rapidly decolorized until about 757, (18
+
(18) C. D. Hurd and J. C. Sowden, THISJOURNAL, 60,235 (1938); M . I.. Wolfrom and D. 1. Weisblat, i b i d . , 61, 676 (1939).
(19) R. T. Major and E. W. Cook, ibid., 65, 2474 (1936). (20) G. Robbins and P. Upson, i b i d . , 63, 1074 (1940).
M. L. WOLFROM AND ROBERT L. BROWN
1520
Vol. 65
cc.) of the theoretical quantity of the iodine had been mixed m. p. unchanged) test.*l The compound reduced added; thereafter, there was no observable decoloriza- hot Fehling solution and under the conditions of the Selition and the remainder (12 cc.) of the iodine solution was wanoffz2reaction the compound gave first a yellow color added and the mixture irradiated a further five minutes. folloivetl closely by the cherry-red color characteristic of 'l'he temperature of the mixture was maintained below the ketoses. akikhydo-D-Galactose pentaacetate, when subboiling point of the solvent by cooling frequently in an ice- jected to the same treatment, gave a yellow color which bath. Soon after the reaction was initiated, the sus- persisted for some time and then very slowly assumed a pended diazo compound disappeared and leaflets of the slightly reddish huc. crystalline product began to precipitate. After the final A n d . Calcd. for C7H906fCH3CO)b: C, 50.49; H, 5.98; irradiation the mixture was cooled to the temperature of CHqCO, 12.37 cc. ( J 1 3 XaOH per 100 mg. Found: C. ice-salt and filtered. The precipitate was shaken with ,5020: H, 6.02; CHKO, 12.41 CC. petroleum ether to remove iodine, then filtpred anti dried 1 -13esoxy-keto-u-galaheptulosepentaacetate was likeunder reduced pressure; yield2.7 g. (88' i ) ,ni. 11. 158-.160c. wise formed, in practically quantitative yield, by the Recrystallization was effected from a minimum of chloro- hydriodic acid (47';;) reduction of the 1-iodo and of the 1,lform by the addition of petroleum ether: rn. p. 160--163c, tliiodo-keto-D-galaheptulose pentaacetate. The reduction spec. rot. f 1 3 " (19", c 2 ) . DLKto the inherent instability \\-as performed in the manner described above and the of the substance, these constants are provisional. All product was isolated in the higher melting modification operations following the irradiation were carried out it1 very and identified by inelting point (78-79") and mixed meltdim artificial light in order t o minimize decomposition. iiig point (unchanged). 1,l-Diiodo-keto-D-galaheptulose pentaacetate formed colIt was noted that there was little or no evidence of reorless crystals. The substance, in chloroform, acetone or action when 30f,E hydriodic acid was substituted for the ethanol solution, decomposed rapidly with the liberation of 47' reagent in the reduction of the monoiodo derivative. iodine, when exposed to diffused sunlight or t o art.ificia1 'r.mi*r
