Junc 5 , 1954
N ON-CON JUGATED CHOLESTADIENOL FROM ~-BROMOCHOI,ESTEROL
hydrolysis, presumably as a result of the presence of the double lactol ring system.24 The structural similarity of compound I1 with sedoheptulosan is further reflected in the similar Rr values obtained with several different solvent systems. It has been demonstratc 1 that the ketohexose, fructose, under the influer :e of HC1, is partially converted to two di-D-fruct )se d i a n h y d r i d e ~ .The ~~ possibility of compound I1 t i n g , in a similar manner, di-D-aho-heptulose dianh dride is excluded since several moles of periodat should be readily consumed. Conclusive proc&of the structure of compound I1 must await the production of suffcient material for degradative studies, and the characterization of derivatives. The formation of compound VI is amenable to explanation since the production of analogous compounds by the acid treatment of hexoses and pentoses is well known.26 The absorption spectrum of compound VI is almost identical with that of 5(hydroxymethyl)-2-furfuraldehyde. This spectrum is a t variance with the absorption spectrum of furfural owing to substitution in the 5-position. Although the absorption spectrum indicates that the furan ring is still intact in compounds VI, the nonformation of formaldehyde on treatment with strong acid indicates that the absorption is not caused by 5-(hydroxymethyl)-2-furfuraldehyde. This is also shown by the comparative absorption spectra of glucose, ribose, sedoheptulosan and compound VI when reacting with orcinol. On the basis of the analogous reaction of acid on fructosez7 (24) R . J. Dimler, “Advances in Carbohydrate Chemistry,” Academic Press, Inc., New York, N. Y., Vol. 7, 1952, p, 37. (25) M . I,. Wolfrom and M. G. Blair, THIS JOURNAL, 70, 2406 (1948). (26) A. P. Dunlop and F. N.Peters, “The Furans,” Reinhold Publ. Corp.. New York, N. Y., 1953 (27) W. N. Haworth a n d W. G. hl. Jones, J. Chcm. Soc., 65 (1944).
[CONTRIBUTION FROM
THE PHARMACEUTICAL
2033
this compound would then be 5-(lJ2-dihydroxyethyl)-2-furfuraldehyde.. This compound contains a pair of cis-hydroxyl groups (or a t least potentially of cis configuration) thereby explaining the affinity of the borate complex for the anion-exchange resin. The presence of the furan ring is shown by the obtained absorption spectrum. The absorption spectrum of compound VI with orcinol exhibits the same maximum as does sedoheptulosan. It thus appears that the formation of compound VI is a requisite for the orcinol reaction of D-altro-heptulose and sedoheptulosan since compound VI is formed irreversibly from sedoheptulosan. The non-linearity of the orcinol reaction with larger amounts of sedoheptulosan is probably attributable to the cleavage of furan compounds in acid media. The formation of furfural from 5-(1,2dihydroxyethyl) -2-furfuraldehyde is indicated by the increased absorption a t 670 mp with longer times of heating for the orcinol reaction. Pretreatment of sedoheptulosan with HC1 before carrying out the orcinol reaction has been reported by DischeJZ8who has also applied the cysteine and diphenylamine reactions to the quantitative determination of sedoheptulosan. These latter reactions appear to be more applicable to the deterinination of larger amounts of sedoheptulosan. The non-linearity of the orcinol reaction with sedoheptuiose (above ca. i 2 pg./mi.j has been r e p o r t e ~ i . ~ ~ Acknowledgment.-The authors wish to thank Dr. Nelson K. Richtmyer and Dr. James W. Pratt of the National Institutes of Health for suggesting the structure of compound 11. (28) Z. Dische, J . B i d Chcm., 204, 983 (1953). (29) A. Nordal a n d R. Klevstrand, Anal. Chim. Acfa, 4, 411 (1 950).
OAKRIDGE, TENNESSEE
INSTITUTE, MEDICALFACULTY, UNIVERSITY OF KYUSHU]
Cholesterol and Related Compounds. I. Structure of a New Non-conjugated Cholestadienol from 7-Bromocholesterol BY KYOSUKE TSUDA, KO ARIMA’AND RYOICHIHAYATSU’ RECEIVEDDECEMBER 28, 1953 Trcatinciit of 7a- and 7p-broniocholesteryl acetate ( I a ) (benzoate, Ib) with pyridine or other bases gives, as the chief reaction product, As~8(g)-cholestadienyl acetate ( I I a ) (benzoate IIb). Nitric acid oxidation of I I a gives methylpyromellitic acid (VI) while hydrogenation of I I a in ethyl acetate in the presence of platinum oxide gives As@)-cholestenylacetate (111). Reduction of I11 with platinum oxide in acetic acid yields cholestanyl acetate (V). Chromic acid oxidation of I I a gives 7-keto-A~~8~g~-cholestadien-3~-ol acetate (VIII) which on catalytic hydrogenation with palladium is converted into 7-ketocholestan-3p-01 acetate (IX). Dienone-phenol rearrangement of VI11 with acetic anhydride and sulfuric acid gives a steroidal phenol ( X b ) whose methyl ether (Xc) forms methylnitrobenzenetetracarboxylic acid ( X I ) by oxidation with nitric acid and an anthracene series hydrocarbon, C I ~ H(XIIa I ~ and b), by dehydration with selenium.
A. E. Bide, et a1.,2 obtained A4,6-cholestadienyl acetate by treating 7a-bromocholesteryl acetate3 (Ia) with 2,6-lutidine, and A4.6-cholestadienylacetate and 7-dehydrocholesteryl acetate by the treatment of Ia with diethylaniline. H. Schalteggar, (1) Takamine Research Laboratory, Sankyo Co., Ltd., Tokyo, Japan (2) A. E. Bide, H. R. Henbest, E. R H. Jones, R. W. Peevers and P. A. Wilkinson, J Chem. Soc., 1783 (1U48). (3) I n the present paper the more dextrorotatory isomer is named
“78.”
aL4 obtained 7-dehydrocholesteryl benzoate by the treatment of 7a-bromocholesteryl benzoate (Ib) with dimethylaniline. One of the authors, Arima,6 treated I a with ammonium thiocyanate and obtained a new, non-conjugated dienol of m.p. 147-148’. The present paper describes the detailed examinations of conditions for formation of et
(4) H. Schalteggar and F. X. Mullner, Hclw. Chim. Acta, 84, 1096 (1951). ( 5 ) K. Arima, Pharm. Bull. (Jofian), 1, 224 (19531, cl u p .
2934
KYOSUKE TSUDA, KO ARIM.~AND RYOICHI HAYATSLJ
PRODUCTS O F THE
TABLE I REACTION O F 7or- OR 7B-BROMOCHOLESTERYL BENZoArE
Vol. 'TO
\VITH B A S E
Product, 70-Non?-DeconhydroCholjugated cholesAhnestdienol teryl Choleryl benzoate benzoate estadienol benzo(11) (VII) benzoate ate" 7
7-Br
compd.
a,P cy
CY Ly
React. condn.
Base
Pyridine sym-Collidine y-Picoline, or-picoline NH4SCN: acetone Pyridine, 9-toluenesulfonic acid Ag salt AgOH'
lUO", 5 hr. Room temp. 10 hr. Room temp. Room temp., 24 hr. Room temp., 12 hr.
806 35 40d
4" 4-5'
6" 6-8c
-
.
.
.
7-1Iydruxy chnlesteryl henzoatc
5''
so*
70b 40d
30 (78)" 3( 7 4 Formed on reaction with sym-collidine. This reaction mechanism is assumed to be analogous t o the formation of cholestanone from 2-iodocholestanone (cf. G . Rosenkranz, et al., THISJOURSAL, 72, 4078 (1950)). Recrystallized. U1traviolet spectral analysis of the crude product: calcd. from the extinction of the bands 239 mp (A4j6-dienol),272 and 282 mfi (7-dehydro). Chromatographic analysis. e Cj. K. Arima, Pharm. Bull. ( J a p a n ) , 1, 224 (1953). H. Schalteggcr (Helv. Chim. Acta, 34, 1096 (1951)) carried out this reaction and chromatographic analysis on the product. The substance described as structurally unknown compound X in this report seems t o be identical with the non-conjugated dienol obtairictl in the present experiments, as evidenced by the chromatographic adsorbability. CY
TABLE
COMPARISON O F
h'OX-CONJUGATED
M.p., o c .
DIENOI,
Max., mfi
CtD
I1 147-148 - 54.7" VIIO 146-148 -114 IVb 120-122 - 17.9 A. Windaus, et al., Ann., 534, 122 (1938).
Salkowsky color test
+
hein
A N U ~SODEIIYI~ROCIf~II,ES.I.I.:ROI. (1
Acetatc, mp., 'C.
16, 1089 (1911)
\'I
Jknzoafe,
LYl)
Nil Indigo blue 121-122 -48.3" 282 Bluish violet 129-130 -77.7 275 ......... -10.7 111-1 12 S. Bernstein, et al., J . Org. Chem., 14,433 (1949).
this non-conjugated dienol and studies on its chemical structure. Both the stable 7a-type and the labile 7p-type3 of 7-halocholesteryl benzoate react in a similar manner with primary and secondary amines. 7aBromocholesteryl benzoate gave 7p-anilino derivative,e m.p. 188-189', CYD 134.5', and 7p-pipe1-idin0 derivative,6 1n.p. 166-168', CYD$92.8'. 70Bromocholesteryl benzoate gave the epimeric 7aanilino derivative, m.p. 174-175', CYD +120° and the 7a-piperidino derivative, m.p. 195-197O, an +52". However, the reaction of the tertiary arnine, pyridine, differs with 7a- and 7P-compounds. When the 7a-bromo compound is allowed to stand with cold pyridine it is converted to a pyridinium salt, m.p. 189-190°, while the same treatment of the 7p-bromo compound gives the non-conjugated dienol. Further heating of the pyridinium salt of 7a-bromocholesteryl benzoate with pyridine finally affords the non-conjugated dienol. The yield of the non-conjugated dienol is SOY0 when 7a- or 7~-bromocholesterylbenzoate is heated with pyridine, and a minute amount of 7-dehydrocholesteryl benzoate and A4 6-cholestadienyl benzoate are obtained as by-products. When 7-bromocholesteryl benzoate is treated with 2,4,6-collidine, a-picoline, y-picoline, silver hydroxide or an aqueous solution of p-toluenesulfonic acid, the chief reaction product is the non-conjugated dienol. The yield and by-products obtained are given in Table I. This non-conjugated dienol is 'in isomer of ;-dehydrocholesterol and isodehydrocholesterol and differs from these substances in that i t does not show any absorption band in the region of 230-360 rnk in the ultraviolet spectrum. Comparison of these isomers is shown in Table TI. (6) K J Knox a n d S B e r n i t e i u , J 01q
11
(II), 7-DEHYDROCHOLES'rEROl, (\:lI)
in p., "C.
149-1 30 140-141 146
Catalytic reduction of the non-conjugated dienol acetate (IIa) in ethyl acetate with platinum oxide results in the absorption of one mole of hydrogen to give a substance melting a t 124-126', CXD +33.5', which was found to be identical with A8(9)-cholesten-3b-01 acetate (111), prepared from isodecholesterol (IV) according to the method of H. Wieland, et al.,' and D. H. R. Barton, et aL8 Catalytic reduction of 111 in glacial acetic acid with platinum oxide, a t 80°, results in absorption of one iiiolc of hydrogen to give cholestanyl acetate (V). IIa gives niethylbenzenetetracarboxylic acid (tetramethyl ester, n1.p. 122-123') by oxidation with nitric acid. This tetramethyl ester failed to show any depression of the melting point 011 admixture with the methyl ester, m p . 122-123', of a carboxylic acid obtained by the nitric acid oxidation of 7dehydroch~lesterol.~I t is known that this carboxylic acid is inethylpproinellitic acid (VI) and that it is formed by nitric acid oxidation only when two double bonds are present in the B ring, as in 7-dehydrocholesterol, isodehydrocholesterol and ergosterol. lo Considering the results of hydrogenation, it may be assumed that the two non-conjugated double bonds in I1 are a t A5,8(9), Chromic acid oxidation of IIa gives an a,@-unsaturated ketone VIII, m.p. 151-152', XgzH2319 Ink, CYD -67.3', which forms a semicarbazone of m.p. 210-212' dec., 2191 in^. Catalytic reduction of VIII in acetic acid with palladiuni easily gives ( 7 ) €1. Wieland and \V.Retiend, l u i ~ 5,5 4 , 1 (1913). (8) D. H. R. Barton and .1. D. C o x , J . Chcm Soc., 212 (19491. (9) L. F. Fieser and M a r y Fieser, "Natural Products Related t o Phenanthrene," Reinhold Publ. Corp., New York, N. Y., 1949, pp. 160 and 169. X o evidence is available concerning t h e mechanism of formation of methylpyromellitic acid. (10) K . Alder and B K r u g r r , Brr , 86,98: (1O:A).
NON-CON JUGATED CHOLESTADIENOL FROM 7-BROMOCHOLESTEROL
June 5, 1954
7-ketocholestanyl acetate (IX), from which it can be seen that the double bond a t has become easily reducible by the influence of the carbonyl group.11 The transformation establishes the position of the carbonyl group in VI11 and confirms the structure 11. The structure VI11 is further supported by the fact the substance easily undergoes the dienone-phenol rearrangement.'?
293.5
Selenium dehydrogenation of X b and chromatographic purification of the product through an alumina column gives an easily crystallizable substance (XIIc), m.p. 210-212', C'SHlsO, and an oily hydrocarbon, which can be converted to a crystalline picrate but does not easily crystallize on regeneration. Both hydrocarbons (XIIa and XIIIb) correspond to the formula ClbHls, and give picrates ot 1n.p.
C8H17
l
~
ROvV-Br
C8H17
l
or
f-
VI
IIa, R = Ac IIb, R = Bz
Ia, R = Ac I b , R = Bz
VI1
AcO
I11
IV
In this reaction, VIII, is dissolved in a mixture of chloroform and acetic anhydride and a mixture of sulfuric acid and acetic anhydride is added; the color of the solution changes from yellow, through pink and green, to dark green, and a diacetyl compound Xa, m.p. 164', is obtained as the reaction product. Saponification of this compound gives a substance of m.p. 263-265', corresponding to c27H4202, showing 275 mp. The substance dissolves in hot caustic alkali and gives a methyl
v
VI11
IX
133.5-134' and 149-150'. This composition suggests an aromatic hydrocarbon. The ultraviolet absorption curves of these hydrocarbons were compared with those of hydrocarbons of the anthracene and phenanthrene series (Fig. 1). Phenanthrenic hydrocarbons show the first peak a t 250260 mp and the second peak a t 270-280 r n p , while anthracenic hydrocarbons show the first peak a t 250-260 mp and the second peak a t 330-350 mp.13 Both X I I a and X I I b clearly show absorption curves
C8Hl7 Ac~O VI11 -+
H+
Sa, R = R ' = Ac Xb, R = R' = H XC, R = H, R' = CHI
CH3
-+
x
01
ether, n1.p. 220' (by diazoinethane or dimethyl sulHNOa (COOH )4 fate), from which it is assumed that the substance is XI Xc -+ CHJ a phenol of the structure Xb. Oxidation of the KO* methyl Xc with nitric acid gives an acid, methylC19Hl8, X I I a ; picrate, m.p. 133.5-134' nitrobenzenetetracarboxylic acid, Cs(N02)( CHa). C19H18, X I I b ; picrate, m.p. 149-150" (COOH)4, giving a tetramethyl ester of m.p. 132C19H180,XIIc; m.p. 210-212' 133'. I t is assumed that this is 1-methyl-4-nitrobenzene-2,3,5,6-tetracarboxylic acid formed by the of the anthracenic type and, therefore, the CYClOnucleophilic substitution of the methoxyl by a ni- pentanoanthracene nucleus (X) can be assumed for the phenol. D. H. Barton, et a1.,14have carried out tro group. the dienone-phenol rearrangement of 7-ket0-A~,*(~)( 1 1 ) L. F Fieser and J . E Herz, THISj O U R N 7 5A , 121 L , (1953). (12) A . L . Wilds and C . Djerassi, i b i d , 68, 1712 (1946); R. B. lanostadienyl acetate but made no experiments to n'oodward and J. Singh, ibid., 7 2 , 494 (1950); C. Djerassi and G. confirm the structureof the phenol formed. Rosenkranz, ibid., 7 2 , 4542 (1950); A. Dreiding, W. J. Pummer and A . T. 'Tomasewski, ibid., 75, 3159 (1953); H. H. Inhoffen, G . Kolling and P. Nehring, Be?., 8 6 , 88 ( l Y 5 2 ) : R B. Woodward, H. €I. Inhoffen, I1 0 I.arirm and IC. I1 RIenzel, i b i d , 8 6 , 594 (1953).
(13) R . A. Friede a n d M. Orchin, "Ultraviolet Spectra of Aromatic Compounds," John Wiley and Sons, Inc., New York, N. Y.,1951. (14) D. H. Barton a n d B. R. Thomas, J. Chcm. Soc., 1842 (1953).
leum ether and benzene and passed through a coluinn coiitaining 360 g. of alumina. The column was clutcd with 8 liters of the same solvent and the effluent was fractioliatetl into 500-cc. portions. Fractions 1-3 gave crystals of 1n.p. 144-146' which recrystallized from a chlorofortn-acetouc mixture to IIb, m.p. 149-1500', yield 4.32 g. Fraction 4 gave crystals of m.p. 139-141 , and fractions 5-9, crystals of m.p. 182-185', which recrystallized from acetonc to 7,9hydroxycholesteryl benzoate, m.p. 189-190°,4 yield 3.8 fi. Fractions 12-16 furnished crystals of m.p. 162-165' which recrystallized from acetone to 7a-hydroxycholesteryl benzoate, m.p. 165-167°,4 yield 357 mg. (4) Five grams of 7a-bromocholesteryl benzoate was dissolved in 50 cc. of pyridine, 7 g. of silver p-toluenesulfoiiate was added, and the mixture was allowed to stand overnight. After filtration, the filtrate was poured into dilute hydrochloric acid solution, and the precipitate was collected 1)y 0 filtration. The precipitate was washed with 1 0 ~ hydro0 chloric acid and water, extracted with ether, and the ethereal residue was recrystallized from a chloroform-acetone mix5.0 ture to I I b , m.p. 149-150", yield 2.6 g. In exactly the same manner, 5 g. of 7p-brotnoeholestcryl Iienzoate furnished 2.5 g. of IIb. A6~8(g)-Cholestadien-3P-ol.-Thirtygrams of I I b \vas dis4.0 solved in the smallest possible amount of benzene, incthanolic potassium hydroxide (400 cc. of metlianol f 5 g . of potassium hydroxide) added, and the mixture was rcfluxcd for 3 hours. A small amount of water was added, and thr 3.0 mixture allowed to stand a t 0' when crystals scparated. The crystals were collected by filtration and rccrystallizcd from a chloroform-acetone mixture t o colorless necdles. m.p. 147-148', @D -54.7' ( c 1.17, CHCla); soluble in chloroform and benzene, easily soluble in hot acetoiie but sparingly 2.0 so iu cold, sparingly soluble in alcohol; yield 18.4 g . A m i . Calcd. for C Z , € I ~ ~ C, O : 83.85; H, 11.43. I'ouiid: 200 240 280 320 360 400 C, 83.10; H, 11.77. X, mp. A5~8~9)-Cholestadienyl acetate (IIa), obtained b y allowing Fig. 1.-Ultraviolet absorption spectra, A : . , ., anthra- a mixture of the dienol, pyridine and acetic anhydride to cene; -.-.- , 4H-methylbenzanthracene; , phen- stand overnight, or by treatment of 7a-bromocholcstcryl anthracene; , cyclopentetiophenanthrene. B: acetate as in the case of benzoate, recrystallized froin act~ (c tone as colorless needles, m.p. 121-122", ( ~ 2 6-48.3' , X I I a ; . . ., X t I b ; -.-., XIIC. 3.31, CHC1,). Formation of a Salt from 7~-BromocholesterylBenzoate Experimental and Pyridine.-A mixture of 10 g. of 7n-broniocholestcr~l benzoate and 40 cc. of pyridine was allowed to stand for 7 S'(Q)-CholestadienylBenzoate (IIb).-(l) A solution of hours at room temperature. This was poured into dilutr 5.5 g. of 7a-bromocholesteryl benzoate,'6 r1i.p. 123-144', hydrochloric acid and the crystals that precipitated wcrc a z 2 D -179.5' (c 1.47, CHCI?), dissolved in 150 cc. of pyritlinc was heated a t 100" for 5 hours, and the reaction mix- collected by filtration. After drying, they were recrystalture was poured slowly into a large amount of water acidi- lized from a chloroform-ether mixture t o colorless needles, D (c 1.02, CI-ICla), yield 3.2 g. fied with diluted hydrochloric acid, under ice-chilling. The m.p. 189-190", ~ O 4-71" reddish-brown oil that separated solidified on standing, and Anal. Calcd. for C~9H5aO~BrK: C , 72.22; 11, 8 the product was collected, washed with 10% hydrochloric N, 2.16. Pound: C, 72.47; H , 8.51; hT,2.07. acid anti a small amount of methanol and acetone, dried, 7a-Anilinocholesteryl Benzoate.-A lirci-like iiiixtur-c or and recrystallized from a mixturc of chloroform and acetotie 3 g. of 7~-bromocholcsterylbenzoate alid 6 cc. of aililirie was to colorless prisms, m . p . 140-150"; yield, 36.5 g.; soluble allowed to stand overnight, poured into dilute hydroclilorir i l l chloroform, benzenc aiitl ethcr, spariitgly solublc iti aceacid, atid the precipitated crystals were collected by fi1tr:Ltouc atid alcohol. tion. The crystals were washed consetutivcly with wal c r , .lm/. Calcd. for C , r f i 4 8 0 : : C, 83.34; H , 9.81. I'ouiitl: dilute sodium hydroxide, water, anti methanol and rt('r\"itallized from chloroform to colorless prisms, 11i.p. 174 - 1 7*7', C, 113.4; 11, 10.20. a Thc same result was obtaiiipd rtheri 7~-brorr1oeholester~I * 5 ~4-120" (c 1.07, CHC18), yield 1.7 g . Anal. Calcd. for CtoIIss02N: C, 83.1i1; 11, 9.lti; .'
