Cyclopentanone yield

S,S)(R,R)-l-(ris-cyclopentadienyl)-3-(l-hydro.xy-l-methy ethyl)-l- triphenylphospfuine)-l-cohalta-2-cyclopentanone yield not reported... 

R, 4S )-3-ten-butoxy-4- l,i-dimethyl-3-[(SS )-phenylsulJinyl]-2-prupe,nyl cyclopentanone yield 80%... 

R1 = CHjOTBDMS R2 = CH = CHCHOTBDMS(CHj),CH3 (2S. 3R, 4R )-4- ten-butyldimethylsilyl-oxy)-2-[(fR/lS)-(7)-4-(ten-butyIdimethylsilyloxy)-l-hydroxy-2-octenyl]-3- (E)-7-(tert-butyldimethyl-silyloxy)-3-[(/RlSS)-phenylsul/tnyl -2-heptenyl cyclopentanone yield 70 %... 

A similar acetylation procedure (without p-toluenesulfonic acid) has been employed to prepare other /3-diketones.5 As examples, cyclohexanone was converted to 2-acetylcyclohex-anone (73%) cyclopentanone yielded 2-acetylcyclopentanone (80%) 3-pentanone yielded 3-methyl-2,4-hexanedione (81%) dibenzyl ketone yielded l,3-diphenyl-2,4-pentanedione (72%), and acetophenone gave benzoylacetone (70%). 

Condensation of formaldehyde with cyclopentanone yields a compound with four -CH2OH groups, which can be nitrated to the tetra-nitrate. Analogous derivatives of hexanone, hexanol, and pentanol can be prepared in the same manner, but in the case of pentanol and hexanone the fifth hydroxyl group also becomes esterified ... 

Very few examples of substituted derivatives of 1, 7, and 9 have been reported.41a 42 Two examples (19) and (20) of 1 are described above. The thermal condensation of o-aminobenzaldehydes and o-aminoaceto-phenones with substituted cyclopentanones yields derivatives of the cyclopentaquinoline system (30).41b Dehydrogenation of 31 with... 

Cyclopentonone Peroxides Milas et al (Ref 2) found that the reaction of cyclopentanone yielded a variety of peroxides ... 

R,3R,4R)-4-alkoxy-3-(3-a/koxy-I-oetenyl)-2-(2-nitroethyl)cyclopentanones yield 97% 76... 

R,3S)-2-ethyl-3-hydroxy-2-(5-phenyllhio-3-oxopentyl)cyclopentanone yield 53% 100% ee... 

To 1.18 g (14.4 mmol) of 2-methylfuran and 1.18 g (14.4 mmol) of cyclopent-2-enone in 10 mL of acetonitrile were added 43.7 mg (144 jmol, 1 mol%) of AuCL. The reaction was monitored by withdrawing small aliquots, which were analyzed by H NMR. After 1 day, the solvent was removed under vacuum and the crude material was purified by column chromatography on silica gel using hexanes/EtOAc (4 1) to afford 3-(5-methylfiiran-2-yl)cyclopentanone yield 2.05 g (87%). ... 

Ketones can also be used in this transformation, but sometimes enolizable ketones lead to the formation of the vinyl chloride derived from the enol. This is usually more of a problem for six-membered ring ketones than for five-membered ring ketones. Cyclopentanone yields predominantly the 1,1-dichloroalkene (eq 33), while cyclohexanone provides mainly the vinyl chloride (eq 34). ... 

Oxidative rearrangement takes place in the oxidation of the 1-vinyl-l-cyclo-butanol 31, yielding the cyclopentenone derivative 32[84], Ring contraction to cyclopropyl methyl ketone (34) is observed by the oxidation of 1-methylcyclo-butene (33)[85], and ring expansion to cyclopentanone takes place by the reaction of the methylenecyclobutane 35. [86,87]... 

Degradatiou. Heating of succinic acid or anhydride yields y-ketopimehc ddactone, cyclohexane-1,4-dione, and a mixture of decomposition products that include acetic acid, propionic acid, acryUc acid, acetaldeide, acrolein, oxaUc acid, cyclopentanone, and furane. In argon atmosphere, thermal degradation of succinic anhydride takes place at 340°C (123). Electrolysis of succinic acid produces ethylene and acetylene. 

CycHzation with loss of one carboxyl takes place in the presence of metal oxides, notably barium and thorium. Thus adipic acid yields cyclopentanone, carbon dioxide, and water (Dieckmaim reaction). 

Irradiations of Testosterone Acetate (114), —In t-Butanol. 1.25 g of (114) in 250 ml t-butanol is irradiated for 32 hr at 30° under nitrogen with a Hanau Q81 high-pressure mercury lamp placed in a central water-cooled Pyrex immersion well with acetone filter. The solvent is evaporated in vacuo and the residue chromatographed on 125 g silica gel with benzene-ethyl acetate (4 1) to yield 0.29 g 17 -hydroxy-la,5 -cyclo-10a-androstan-2-one acetate [(118) 23%] mp 164-165°, after crystallization from acetone-hexane [a]i3 37 (CHCI3) 0.14 g cyclopentanone (120) (11%) mp 106-107° [aJo 38° (CHCI3) and 0.58 g starting material [(114) 46%]. Ratio (118) (120) - 2 1. 

The secondary amines used in the preparation of enamines have been primarily simple dialkylamines or cyclic amines of five- or higher-membered rings. Azetidine (4) yields a stable enamine with cyclopentanone (28). No simple enamines formed by condensation of ethylenimine (5) or a substituted ethylenimine with an aldehyde or ketone have been reported. 

The only kinetic data reported are in a Ph.D. thesis (41). Integral order kinetics were usually not obtained for the reaction of a number of ketones with piperidine and a number of secondary amines with cyclohexanone. A few of the combinations studied (cyclopentanone plus piperidine, pyrrolidine, and 4-methylpiperidine, and N-methylpiperazine plus cyclohexanone) gave reactions which were close to first-order in each reactant. Relative rates were based on the time at which a 50% yield of water was evolved. For the cyclohexanone-piperidine system the half-time (txn) for the 3 1 ratio was 124 min and for the 1 3 ratio 121 min. It appears that an... 

The addition of diphenylcyclopropenone to pyrrolidinocyclohexene and ring expansion of the adduct gave an aminocyclononadicnone (330,331), A hereas the corresponding cyclopentanone derived enamine yielded a bieyclic enone. 

In addition, the cyclopentylidene ketal has been prepared from dimethoxy-cyclopentane, TsOH, CH3CN, or cyclopentanone (PTSA, CUSO4 >70% yield) and can be cleaved with 2 1 ACOH/H2O, rt, 2 h. Certain epoxides can be converted directly to cyclopentylidene derivatives as illustrated in the following reaction ... 

Cyclic ketones react through ring expansion to yield lactones (cyclic esters). For example cyclopentanone 7 can be converted to 3-valerolactone 8 ... 

Following the procedure given above, cyclopropylidenecyclopentane is prepared in 85% yield from 34.4 g (0.09 mole) of the phosphonium salt, 3.83 g (0.097 mole) of sodium amide (used instead of phenyllithium), and 8.4 g (0.1 mole) of cyclopentanone in ether as solvent (350 ml). The product has bp 69-70770 mm. 

Choice of catalyst and solvent allowed considerable flexibility in hydrogenation of 8. With calcium carbonate in ethanol-pyridine, the sole product was the trans isomer 9, but with barium sulfate in pure pyridine the reaction came to a virtual halt after absorption of 2 equiv of hydrogen and traws-2-[6-cyanohex-2(Z)-enyl]-3-(methoxycarbonyl)cyclopentanone (7) was obtained in 90% yield together with 10% of the dihydro compound. When palladium-on-carbon was used in ethyl acetate, a 1 1 mixture of cis and trans 9 was obtained on exhaustive hydrogenation (S6). It is noteworthy that in preparation of 7 debenzylation took precedence over double-bond saturation. 

What alkene would yield a mixture of cyclopentanone and propana) on treatment with ozone followed by reduction with zinc ... 

Compound A, C10H 8O, undergoes reaction with dilute H2S04 at 50 °C to yield a mixture of two alkenes, QpH ir>. The major alkene product, B, gives only cyclopentanone after ozone treatment followed by reduction with zinc in acetic acid. Identify A and B, and write the reactions. 

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