ERYTHROMYCIN. IV. DEGRADATIVE STUDIES - Journal of the

Paul F. Wiley, Koert Gerzon, Edwin H. Flynn, Max V. Sigal Jr., and U. Carol Quarck. J. Am. Chem. Soc. , 1955, 77 (13), pp 3676–3677. DOI: 10.1021/ ...
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potassium ethyl xanthate. The intermediate xanthate (11)was not isolated b u t was reduced directly with sodium borohydride in alcohol solution followed by saponification to give 9-thiol-a-methyl . ~ D 1.1408, benzyl alcohol (111) ( P ~ ~ ~1.58S0, m.p. 44.8-46.2"; Calcd. for CsHloOS: C, 62.30; H, 6.54; S, 20.79. Found: C, 62.2,3; H, 6.68; S, 20.90) in 63y0 yield. 111 was converted to the D P . j 4 1.1460; Calcd. diacetate (IV) ( T L ? ~ . ~1.5422, for CI2Hl4O3S: C, 60.48; H, 5.92; S, 13.45. Found: C, 60.42; H, 5.81; S, 13.36) in 90% yield which was then successfully deacetylated by passing through a hot tube a t 450" to give p-vinylphenyl thioacetate (VI ( ? Z ? ' . ~ DI .5992, d25.541.0953; Calcd. C, 67.35; H,5.60; S,1T.99. Found: for CloH1~OS: C, 67.51; H, 5.44; S, 18.28) in 48'g yield. V was successfully polymerized with ?,?'-azo-bis-isobutyronitrile as the catalyst to give poly-p-vinylphenyl thioacetate, [TI, 0,303, in benzene. Calcd. for (CloHloOS),: C, 67.3s; H, 5.00. Found: C, 67.16; H, 5.67. .I polymer sample of lower molecular weight, 1171 = 0.124, in benzene, was saponified by dropping its benzene solution into boiling dilute alcoholic base to give poly-P-thiolstyrene. (Calcd. for CpHeS: C, 70.54; H , 5.92. Found: C, 70.41; H , 6.09.) This polymer is a white powder soluble in basic solution and partially soluble in organic solvents such as benzene and cyclohexanone. It is precipitated from such a solution by methanol or petroleum ether. .4n intrinsic viscosity of the soluble portion (9670) in benzene, gave a value [v] = 0.090. The polymer was easily oxidized with characteristic oxidizing agents such as iodine to give an insoluble polymer. The reversible oxidation reduction system and the use of this polymer and some of its copolymers as model proteolytic enzymes will be reported separately. SYe wish to thank the Public Health Service, National Institutes of Health for their generous support of this work, Contract US PHG-4154.

chloride resulted in degradation to X-O-desosaminyldihydroerythronolide2 (111), m.p. 212-213" [Calcd. for C2YH66N010: C, 60.29; H, 9.59; N, 2.42; C-CH3 (i),15.2; mol. wt., 577. Found: C , 60.39; H, 9.67; N, 2.35; C-CH3, 16.34; mol. wt., 583 (electrometric titration) ; [a]%. -2' (c,1 in methanol); [ Q ] ? ~ D- 5 " (C, 1 in pyridine) ; pK', S.O in 06% dimethylformamide]. The infrared absorption spectrum of 111 indicated hydroxyl and ester or lactone carbonyl (2.55 p and 5.86 p) since there was no evidence of ketonic carbonyl in the ultraviolet spectrum. Consumption of one mole of periodate per mole of 111indicated the presence of a pair of adjacent hydroxyl groups. Hydrolysis of 111 with 2 -V hydrochloric acid in a two phase system gave, in addition to d e ~ o s a m i n e , ' . ~ products I\-, I' and V I all containing twenty-one carbon atoms. Dihydroerythronolide (IV) was the principal product, m.p. 183--1$7' [Calcd. for C?1HaOe: C, 59.97;H, 9.59; C-CH3(6), 21.4; mol. wt., 420. Found: C, 60.04; H , 9.56; C-CH3, 20.21; mol. wt., 405; [ c Y ] ~ f ~ D9.5"(c,2 in methanol) 1. The infrared spectrum had a broad band a t 2.75-3.90 p and a ba-i:i a t .5.S(i p . The ultraviolet absorption spectrum TWS transparent in the 220-400 inp region. This coin;, )u:itl consumed two moles of periodate per mole. Cowpound I' melted a t 233-231" [Calctl. for Csl 7 : C, 62.66; H, 9.52; 0, 27.83; C--CH:{( ( i l , 3 ; mol. wt., 402.5. 0 , 2 i . 5 4 : C-CHA, 19.89; mol. wt., -403.0 (X-ray crystallographic analysis) ] and Colnpou!id -\-I melted a t 192-193" [Calcd. for C?IFIisO;: C ,62.66; H, 9.5'2; 0, 27.8R; C--CH3(6), ?'2.-l-.i; i11