Acetic startg

A soln. of 3 gm. a-phenacylpyridine oxime in abs. ether shaken while gradually treated with no more than 3 gm. of PCI, shaking continued for 3 hrs., then made faintly alkaline with K2C0s — crude a-pyridylacetic acid anilide (Y 90%) dissolved in abs. alcohol, HCl-gas passed in, and boiled 3 hrs. —ethyl a-pyridyl-acetate (startg. m. f. 356) (Y 80-85%). (F. Galinovsky and G. Kainz, M. 77, 137 (1947).)... 

A soln. of methyl desoxoglycyrrhetate (prepn. s. 87) in toluene treated with ethanolic 15%-KOH, refluxed 120 hrs. in a copper flask under Ng, and the crude product acetylated by heating 1 hr. on a steam bath with acetic anhydride in pyridine desoxoglycyrrhetic acid acetate (startg. m. f. 319). Y 88.3%. E. J. Corey and E. W. Cantrall, Am. Soc. 81, 1745 (1959). 

A soln. of l-keto-l,2,3,4-tetrahydrophenanthrene in acetic anhydride treated dropwise -with swirling in an ice bath with a soln. of coned. H2S04 in acetic anhydride, allowed to stand 2 hrs. at room temp., worked up, and the process repeated - l-keto-l,2,3,4-tetrahydrophen-anthrene-2-sulfonic acid hydrate (startg. m. f. 183). Y 85%. (F. e. s. C. Djerassi, J. Org. Chem. 13, 848 (1948).)... 

Acetic anhydride added dropwise over a period of 45-55 min. to a vigorously stirred and gently refluxing mixture of fluorene and A1C13 in CS2, and the resulting complex washed with CS2 and petroleum ether, before it is hydrolyzed —2-acetylfluorene (startg. m. f. 217). Crude-Y 83-95%. (F. E. Ray and G. Rieveschl, Jr., Org. Synth. 28, 3 (1948).)... 

Acetone reacted with acetylene in methylal (formaldehyde dimethyl acetal) at 5°, in the presence of a 3 7 mixture of NaOH pellets and powdered KOH 2,5-dimethyl-3-hexyne-2,5-diol (startg. m. f. 159). Y 90-95%.—At lower temp., acetylene adds only 1 mole of acetone to give 3-methyl-l-butyn-3-ol. (H. Richet, A. ch. [12] 3, 317 (1948).)... 

Startg. a-isonitrosoketone allowed to react with H2SO4 in moist acetic acid imide. Y 16%. E.R.H. Jones et al., Chem. Commun. 1968, 210. 

Startg. thioketal shaken vigorously at room temp, for 2-12 hrs. with 2 moles aq. mercuric acetate until precipitation of the Hg-mercaptide is complete ketone. Y 92% as the semicarbazone. - This mild procedure avoids difficulties due to volatility of regenerated ketones. F. e. s. G. P. Pollini et al., Farmaco, Ed. Sci. 25,405 (1968). 

Startg. hydroxyamide dissolved during ca. 1 hr. in ice-cooled coned. H2SO4, and the product isolated after another hr. 2-methyl-3-phenyl-3,4-dihydroisocarbo-styril. Y 86%. F. e., also in acetic acid containing H2SO4, s. C.-L. Mao, I. T. Barnish, and C.R. Hauser, J. Heterocyclic Chem. 6, 83 (i969) Can. J. Chem. 47, 3671 (1969). 

Hydroazulenes. Startg. trans-iustd. ketotosylate refluxed with 2 equivalents K-ace-tate in glacial acetic acid -> product. Y 78%. C. H. Heathcock and R. Ratcliffe, Chem. Commun. 1968, 994. 

Startg. hydroxyhemiacetal treated 2hrs. at 40-50° with Na-periodate in acetic acid-acetone-water -> norcholanal. Y ca. 100%. - This is a stage in a stepwise degradation of aldehydes. F. stages s. Y. Yanuka, R. Katz, and S. Sarel, Chem. Commun. 1968, 851. 

Startg. aldehyde allowed to react with 2-phenyl-2-thiazolin-5-one in tetrahydro-furan in the presence of basic lead acetate product. Y 11%. - This is a stage in a total synthesis of dl-Terramycin, a tetracycline derivative. H. Muxfeldt et al.. Am. Soc. 90, 6534 (1968). 

Startg. acetal kept 2 days at room temp, with phosphoric acid product. Y F. e. s. D. W. Brown et al., Tetrah. Let. 1968, 2609. 

Startg. selenonium salt heated with KHSO4 until gas evolution starts 2-benzoyl-3-methylbenzo[b]selenophene. Y 83%. F. e., also with acetic anhydride-pyridine, s. L. Christiaens and M. Renson, Bl. Soc. chim. Belg. 77, 153 (1968). 

Startg. steroidal l,4,7,9(ll)-tetraen-3-one allowed to react with HBr and acetic acid in rert-butanol equilenin. Y 95%. Also equilenin ethers in lower alcohols s. E. J. Bailey et al., Chem. Commun. 1967, 1253. 

A soln. of Z i -androstene-3/ -ol-17-one acetate in the minimum amount of diloro-form distributed as a film on the inside walls of a large conical flask, which is then filled with oxygen, stirred 5 days at room temp, with addition of more chloroform to prevent crystallization of the startg. m. 14j5-hydroperoxy-zli5-androstene-3 -ol-17-one 3-monoacetate. Y 82%. A. Afonso, Can. J. Chem. 47, 3693 (1969). 

Startg. diazo oxide added portionwise during 10 min. to refluxing 30%-HBr-acetic acid, and the product isolated when gas evolution has ceased -> o-bromophenol deriv. (Y 82%) refluxed 5 min. with triphenylphosphine in nitromethane S-tert-butyl-5-hydroxy-4a-azoniaanthracene bromide (Y 98%). - This is part of a 4-step sequence to remove one hydroxyl from a pyrocatechol grouping. F. e. s. D. L. Fields and J. B. Miller, J. Heterocyclic Chem. 7, 91 (1970). 

Methyl anthranilate added to a soln. of the startg. o-thiocyanoisothiocyanate in acetone, and refluxed 5 min. on a water bath crude 1,2,4-benzodithiazine derivative (Y ca. 100%) dissolved in warm ethanol, 10%-Na-thiosulfate soln. and 30%-acetic acid added crude benzothiazole derivative (Y ca. 100%). F. e. s. R. Pohloudek-Fabini and M. Seldiau, Arch. Pharm. 302, 527, 517 (1969). 

A 2.4-fold excess of trimethyloxosulfonium iodide stirred 45 min. with the same excess of NaOH in dimethyl sulfoxide to produce dimethyloxosulfonium methylid, the startg. 17-chloro-20-oxosteroid added, stirred 1.5 hrs. at 40°, and the crude product acetylated during 16 hrs. with acetic anhydride-pyridine 3) -acetoxy-16a-methylspiro[androst-5-en-17,l -cyclobutan]-3 -one. Y 55%. R. Wiechert, Ang. Ch. 82, 219 (1970). 

Oxidative fragmentation. Ceric ammonium nitrate added in one portion at room temp, to the startg. keto alcohol in aq. 75%-acetic acid, stirred an additional 1.5 hrs., coned. HCl added, and allowed to stand 3.5 hrs. at room temp. diketone. Y 85.7%. 

Heterolytic fragmentation. Satd. aq. Na-carbonate added to a soln. of the startg. bromo acetate in methanol, and stirred 1 hr. at 0° product. 

A soln. of the crude startg. m. in pyridine containing acetic anhydride kept 0.5 hr. at room temp. -> 3-0-acetyl-5,6-dideoxy-l,2-0-isopropylidene-6-nitro-a-D- y/o-hex-5-enofuranose. Y 80%. W. A. Szarek, D. G. Lance, and R. L. Beach, Carbo-hyd. Res. 13, 75 (1970). 

A soln. of the startg. steroidal bicyclobutane deriv. in acid-free ethyl acetate hydrogenated 3-4 min. with prehydrogenated 10%-Pd-on-carbon until H -uptake slows abruptly after 1 equivalent has been absorbed product. Y >80%. E. Galantay et al.. Am. Soc. 92, 5771 (1970). 

Startg. ketolactone refluxed 48 hrs. with acetic anhydride containing p-toluene-sulfonic acid dienollactone. Y 58%. K. Yamada, T. Kato, and Y. Hirata, Chem. Commun. 1969, 1479. 

Fragmentation. Startg. m. heated 3 hrs. at 182° with excess Zn-dust under a Ng-stream 1,1-diphenylpropene. Y 80%. F. e., also with Zn-acetate instead of Zn-dust, s. E. Ghera, Tetrah. Let. 1970, 1539. 

Startg. bromolactone hydrogenated with Pd-on-charcoal in alcohol containing 1 equivalent K-acetate as buffer dihydro-i/ -santonin. Y ca. 100%. D. A. Denton, F. J. McQuillin, and P. L. Simpson, Proc. Chem. Soc. 196A, 297. 

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