The Direct Utilization of Glycals for the Preparation of Purine

May 1, 2002 - Eldon E. Leutzinger , William A. Bowles , Roland K. Robins , Leroy B. Townsend. Journal of the American Chemical Society 1968 90 (1), 12...
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Vol. 86

furanosyl)purine, m.p. 155-156', which shows [ L Y ] ~ ~ D Ci-chloro-9-(3',3'-di-O-acetyl-2'-deoxy-cuand -P-D-ribo4-61.1' (HzO), 263.5 mp ( E lO,OOO), infrared bands pyranosyl)purines, l 2 m.p. 178-184'. The ultraviolet ~ 9.22 and 12.25 p (lit.13 m.p. l50-152', [ a ] 2 5 +60.0° absorption, X ~ ~ I - h a n " l263.5 mp ( E 9900) is indicative of (H*O), A K 264 mfi ( e 8869)). The concentrated 9-substitution.'7,'8 Separation of anomers was acfiltrate gave 0.6 g. of B-chloro-9-(2'-deoxy-P-D-ribo- complished by fractional crystallization from absolute furanosy1)purine which was recrystallized from a ethanol to give 0.88 g. of the more ethanol-insoluble small volume of ethyl acetate to yield 0.45 g. of color26.3 mp ( E XS!N), isomer'* ( I ) , m.p. 2O6-ZOi0, lessneedles,'* m.p. 144-14,5', [aIz5jn- 10.8' (methanol), XK?:' 2A-t mp ( t 10700), [ a I z 6 D $22.4" ( c 0.75, acetone). infrared bands a t 8.77 and 1 0 . i 5 p , 264 mp ( E l0,l)OO) The ethanolic filtrates were combined and evaporated (lit.13 m.p. 142-145', [ a l z 6-~11.0' (methanol), Xi: to dryness. The solid residue was crystallized several 264 mp ( E 8930)). These a- and p-anomers were times from methanol to yield 0.18 g. of white needles'2 readily distinguished on the basis of characteristic in( I I ) , n1.p. 149--150', [ a ] 2 f i D-28.3' (c 1.0,ethyl acetate). frared bands. l 3 The assignment of I as 6-chloro-9-(3',4'-di-O-acetyl2'-deoxy-~~-~-ribopyranosyl)purine and I1 as (i-chloroSimilar acid-catalyzed fusion of purineI4 (2.77 g . ) and 1 , ~ , 5 - t r i - ~ - a c e t y ~ - 2 - d e o x y - ~ - r i b o f u r a(1n2o s9.) e ~ ~ 9-(3',~'-di-O-acetyl-2'-deoxy-p - D- ribopyranosy1)purine is tentative as far as the anomeric configuration is cona t 135 .14.io (30 min.) followed by deacetylation with cerned. Proton magnetic resonance spectra of I and methanolic ammonia gave a sirup which deposited I1 in CDC13 show clearly two acetylmethyl groups a t crystals of crude nucleoside (1.7 g., mostly P-anomer), 6 1.95 and 2.1, respectively. The presence of two from methanol. The methariolic m.p. 171-174', protons a t C-2 is indicated by the fact t h a t the C-1 filtrate gave an additional 1 . 1 g. of crystalline nucleoproton is split into two doublets in the 6 5.7-5.9 region. side, m.p. 120-130' (largely a-anomer). The identiTreatment of A-chloro-9-(3',4'-di-O-acetyl-2'-deoxy-pfication of these products as the LY- and P-anomers of D-ribopyranosy1)purine (TI, 400 mg.) with methanolic 9-(2'-deoxy-D-ribofuranosyl)purinewas readily made ammonia a t 110' gave 210 mg. of crystalline &aminoin each case after an additional recrystallization by 9-(2'-deoxy-p-D-ribopyranosyl)purine(111). Recryscomparison of data recorded for these compounds pretallization from methanol and water gave 120 mg. pared b y another route.I3 of pure'* 111, m.p. 266-267', 256 mp ( E 17100), This general synthetic procedure has been found to 258.5 mp ( E 17100), [LYIz6D - 17.0' (c 0.6, water), be applicable equally well to the preparation of purine [if 0.26, R a d 0.56 (n-butyl alcohol-water 86: 14). Compound 111 was shown t o be identical with a product assigned the structure 9-(2'-deoxy-/3-~-ribopyranosyl)adenine recently preparedIg by the mercury salt procedure (lit.]$ m.p. 262-264', 256 mp ( E 16,600), 259.5 m p ( e 16,400), [ a j Z 0-~17.8' ( 6 0.58, water), OAc IZr 0.27, R a d 0.60- (n-butyl alcohol-water 86: 14). Acidic hydrolysis of I11 revealed the presence of adenine and 2-deoxy-~-ribosewhich were identified by paper chromatography in several solvent systems. The direct attachment of the 2-deoxy-~-riboJ CI "2 pyranosyl and 2-deoxy-D-ribofuranosyl functions to various purines and other related heterocycles by this simple procedure is presently under investigation in our laboratory.

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(17) R K. Robins, E F Godefroi, E . C . Taylor, I>. K . Lewis, and A . Jackson, J . A n i . Chem. S O L 83, , 2571 (1961) (18) L. R . Lewis, F H . Schneider, and R . K Robins, J . O r g Chem., 26, 3837 (1961). and references listed therein. (19) H Zinner and E . Wittenburg. Chem. Ber , 96, 1866 (1962)

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DEPARTMENT OF CHEMISTRY MORRISJ . ROBINS ARIZONASTATE UNIVERSITY WILLIAMA . BOWLES TEMPE, ARIZOXA ROLAND K. ROBINS RECEIVEDDECEMBER 13, 1963

2'-deoxy-n-ribopyranosides. This represents the first example of the preparation of a purine pyranosyl nucleoside by the fusion procedure. The Direct Utilization of Glycals for the Preparation of 6-Chloropurine (1.54 g.) and 1,3,1-tri-O-acetyl-Z-dePurine Deoxynucleosides' oxy-@-u-ribopyranoseI5,l6(2.60 g. ) were thoroughly Sir : mixed and heated a t llv5-120' (oil bath) until a light yellow melt was obtained. Then p-toluenesulfonic We wish to report the first recorded synthesis of a acid (20 mg.) was added and the contents were heated heterocyclic nucleoside by direct utilization of a glycal a t 120' zn U ~ C U Ofor 15 min. The residue was dissolved in an acid-catalyzed fusion reaction. This simple i n 12.5 ml. of warm ethyl acetate and the solution was procedure avoids the necessity of synthesis of the usual filtered to remove unreacted 6-chloropurine (0.20 g . ) . 2-deoxy halosugar (often prepared from the glycal) The ethyl acetate solution, after washing, was finally and would appear to compete favorably with other Concentrated to a tan sirup. This sirup was dissolved known synthetic methods. The suggestion for the use of glycals in a direct alkylation of the purine ring in 51) ml. of absolute ethanol which, upon cooling, deposited 1.28 g. of a crystalline anomeric mixture of was first made by Robins, et a1.,2in a model study with 119) Ii H Iwamoto. E M Acton. and I, Goodman, .I Org C h r m , 27, 3940 f I U A 2 ) ill) A G Reaman. .I A m ChPm. S o c . , 76, 5683 (19.54). 115) H Zinner and E Wittenburg, C h r m Rer 94, 2072 (1961) (16) 11. Allerton and W C, O w r e n d . .I I ' / w m Yoc , 1480 (1951).

(1) Supported b y reqearch grants CY-4008(C4) and CA 04008-06 from the National Cancer Institute of the National Institutes of Health, Public Health Service ( 2 ) K K Robins, E F. Godefroi, E. C . Taylor, I,. K. I,ewis, and A Jackson, J A m . Chem S O L ,83. 2574 (1961).

March 20, 1964

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tained by mild acid hydrolysis of I which gave theo2,3-dihydropyran and 2 , 3 - d i h y d r o f ~ r a n . ~However, ,~ phylline and a carbohydrate residue identified as 4,6earlier attempts to employ the use of various glycals di-0-acetyl-2,3-didehydro-2,3-dideoxy-~ - erythro - hexose under similar reaction conditions as for 2,3-dihydro(di-0-acetylpseudo-D-glucal) by comparison with an pyran2 involving the use of ethyl acetate as a solvent authentic sample’ as judged by paper chromatography did not result in nucleoside formation. in two different solvent systems. N o other products T h e recent fusion procedures5 successfully applied were detected in the hydrolysate. Deacetylation of I to nucleoside syntheses suggested the possibility of the (1.0 g.) with methanolic ammonia gave 0.52 g. of 7direct reaction of the requisite purine and glycal in the (2’,3’-didehydro-2’,3’- dideoxy- D - glucopyranosy1)theoabsence of a solvent, since it appeared quite possible ,-1nul. Calcd. for C13phylline (11), m.p. 197-198’. t h a t a similar resonance-stabilized carbonium ion a t C-1 might be involved in the alkylation process. This reaction now has been shown to occur with G-chloroX suspension purine and 3,4-di-O-acetyl-~-arabinal. of 6.10 g. of G-chloropurine6 &nd 8.80 g. of 3,4-di-0a c e t y l - ~ - a r a b i n a lwas ~ heated to 120’ in the presence of 50 mg. of p-toluenesulfonic acid in a manner similar to t h a t described6 for the fusion of 6-chloropurine and 1,3,3-t r i - 0 - acetyl-2-deoxy-6-D-ribopyranose. After a similar isolation procedure,5 1.02 g. of crystalline product was isolated, m.p. 175-l&’,. Examination revealed t h a t this material was an anomeric mixture Ro@ RO H H and -/3-~of G-chloro-9-(3’,4’-di-O-acety1-2’-deoxy-aribopyranosy1)purine. Fractional crystallization from 0 absolute ethanol gave 0.9 g. of 6-chloro-9-(3’,4’-di-OI, R=C-CHs II acetyl-2‘-deoxy-a-D-ribopyranosyl)purine, m.p. 2052 0 i 0 , [ a j Z 6+22.5’ ~ (c 0.75, acetone). .-1naZ. Calcd. 11, R = H for CI4Hl5ClN4O5:C, 47.4; H , 4.23; N , 15.8. Found: C, 47.3; H, 4.26; S , 15.9. The ultraviolet, infrared, HleNj06: C , 50.6; H , 5 . 2 ; N , 18.2. Fouzd: C , 50.3; and proton magnetic resonance spectra and paper H , 5.6; N, 17.9. Such unsaturated nucleosides should chromatography established the fact that this comprove most interesting synthetic intermediates for pound was identical with that anomer prepared5 by further work. Additional current interest in 2’,3’fusion of G-chloropurine and 1,3,4-tri-O-acety1-2-deoxy- unsaturated nucleosides stems from the fact that such p-D-ribopyranose. The presence of A-chloro-9-(3’,4’compounds have been postulated as possible biodi-0-acetyl-2’-deoxy-~-~-ribopyranosyl)pur~ne~ in the chemical intermediates in the enzymatic conversion of ethanolic filtrates was also confirmed by paper chrovarious purine and pyrimidine ribonucleotides to the matography in two systems. corresponding deoxyribonucleotides. The appliIn an effort to study the scope of this reaction, 3.1,6- cation of this procedure for the preparation of unusual tri-0-acetyl-D-gluca18(7.5 g.) and theophylline ( 5 . 0 g.) nucleosides aza the use of additional glycals and the were similarly fused in vucuo in the presence of 50 mg. detailed study of the structure of resulting nucleoside of p-toluenesulfonic acid. During this process, howderivatives are problems under active investigation in ever, a copious evolution of acetic acid was noted. our laboratory. From the reaction mixture was isolated, after recrystal(11) E Fischer, Chrm B i v . 47, 196 11914) lization from ethanol, 5.0g. of a crystalline nucleoside (12) P Reichard, J B i d C h e m , 2 3 7 , :3>1:3 (1562) (presumably an anomeric mixture, I ) , m.p. 102-104’, (13) A. Larsson, ibid , 238, 3 1 1 1 (1963) [a]25+ ~ l e g o (c 1.0, ethanol). The ultraviolet abDEPARTMENT OF CHEMISTRY WILLIAMA . BOWLES sorption spectra, 273 mp ( E 7800) and’:!A: 231. ARIZONASTATE L~XIVERSITY ROLAND E;. ROBINS 273 mk ( 6 4300, 9000), indicated T - s u b s t i t u t i ~ n . ~ TEMPE, ARIZONA =1nul. Calcd. for C17H20X407: C, 52.0; H, 5.10; N , RECEIVED DECEMBER 13, 1963 14.3. Found: C , 51.7; H , 5.24; N , 14.4. Proton magnetic resonance spectra in deuteriochloroform (TMS internal standard) showed the presence of The Specific Chemical Synthesis of y-P3* Labeled only two acetylmethyl groups a t 6 2.02 and 2.15, respectively. The two vinyl protons occur in the Adenosine 5‘-Triphosphate region 6 6.1-6.3. Sir : On this basis and on the analogy of a similar acidcatalyzed reaction of 3,4,6-tri-O-acetyl-u-glucal and Nucleoside j’-triphosphates labeled specifically with p-nitrophenol as the aglycone,I0 the structure of I P3zin the p- or y-position constitute a valuable tool is tentatively assigned as 7- (4’, 6 ’-di-O-acetyl-2I,3’for the elucidation of the mechanism of many biological didehydro-2’,3’ - dideoxy - D - glucopyranosy1)theophylreactions. Successful syntheses of these compounds line. Additional evidence for this structure was obhave invariably been enzymatic in nature’ and frequently are restricted to adenosine polyphosphates (3) I, R I.ewis, F H Schneider, and R K Robins, J Ovg C h e m . , 26, by enzyme specificities. As yet, chemical attempts 3837 (1961) (4) W. A Bowler, F. H Schneider, I,. R Lewis, and R K . Robins, J have led only to products with nonspecific labeling.2 . 3 M e d . Chem , 6 , 471 (1563) We now describe an entirely specific chemical synthesis (.5j M J . Robins, W . A Bowles, and R K Robins, J A m . Chem. S o c , of ATP-y-P32which may be extended to any nucleo86, 12.51 (1564). and references cited therein side j’-triphosphate and to 6-P32nucleoside 5’-tetra(6) A Bendich, P . J . Russel, J r , and J . J Fox, i b i d . , 76, 6073 (19.54); see also A. G . Beaman and R K . Robins, J . A p p l Chem., 12, 432 phosphates.



(1962) (7) I, Vargha and J . Kuszmann, Chem Bel, , 96, 411 (1963) (8) B Helferich, E h‘ Mulcahy, and H . Ziegler, ibid., 87, 233 (1951) (9) J M. Gulland, E. R. Holiday, and T F. Macrae, J . Chem Soc., 1635 (1934) (10) R . J. Ferrier, W. G. Overend, and A E . R y a n , i b i d . , 3667 (1962)

(1) See, e.g.. A. Kornberg. S. G . Kornberg, and E S. Simms, Riochim. B i o p h y s . A r l n , 2 0 , 21.5 (15,56j, G. PfleidPrer, ibid., 47, 389 (1561) (2) J. M. Lowenstein. Btochem. J , 66, 157 ( 1 5 j 7 ) . (3) A mixed chemical and enzymatic method has been used by R . T a n a k a [ J . Biochem. (Tokyo), 47, 207 (1560)l f o r t h e synthesis of ATP-B-PS2.