1 - butan-2-one

A variety of carboxylate activating groups convert certain aziridine carboxylates (307) into 3-halogenoazetidin-2-ones (309). The reaction is stereospecific and is believed to proceed via a l-azabicyclo[1.1.0]butan-2-one cation (74JOC902). 

The product described here, 4-(4-chlorophenyl)butan-2-one, was previously prepared in the following ways a) by reduction of the corresponding benzalacetone, b) by catalyzed decarbonylation of 4-chlorophenylacetaldehyde by HFeiCO) in the presence of 2,4-pentanedione, - c) by reaction of 4-chlorobenzyl chloride with 2,4-pentanedione under basic catalysis (K2CO3 in EtOH), d) by reaction of 4-chlorobenzyl chloride with ethyl 3-oxobutanoate under basic catalysis (LiOH), - and e) by reaction of 3-(4-chlorophenyl )-propanoic acid with methyl lithium. - ... 

Butan-2-one 70 )xmol butan-2-one/l in urine (HGV) Post shift... 

NH4)61V1o7024 4H20 and phthalonitrile (1 4 molar ratio) were ground together and heated in a closed vacuum system at 270 C for 0.75 h. The blue solid formed was washed with aq KOH and H20, and then with EtOH and acetone until the washings were colorless. Alternatively, purification could be carried out by Soxhlet extraction with butan-2-one for 6 h yield 70%. 

Catalytic chain transfer has now been applied under a wide range of reaction conditions (solution, bulk, emulsion, suspension) and solvents (methanol, butan-2-one, water). The selection of the particular complex, the initiator, the solvent and the reaction conditions can be critical. For example ... 

Oxidation of butan-2-one in nitrate media by [Fe" (H20)2phen2j is reported to proceed much more slowly than enolisation moreover Fe(phen) is said to be even less reactive, in total contrast to the results on cyclohexanone. 

Compound 1 is completely hydrogenated to the saturated ketone, 4-(6-methoxy-2-naphthyl)-3-butan-2-one. Compound 2 is hydrogenated in high ytield (90%) to the saturated ketone, 2-acetyl-5,8-dimethoxy-tetrahydro-naphthalene, which can be obtained in the pure form by fractional crystallization from chloroform. 

In the first example of water as the reaction medium for Fischer indole synthesis, 2,3-dimethylindole was obtained in 67% yield from phenylhydrazine and butan-2-one, at 220 °C for 30 min (Scheme 2.15). Neither a preformed hydrazone nor addition of acid was required [33]. 

Bisacodyl Silica gel GF254 (Merck) Butane-2-one Xylene (1 1) Solvent front to run only 10 cm from line of application (1), (2), (3) and (4) contain 2.0% w/v 0.20% w/v and 0.020% w/v and 0.010% w/v of sample in acetone (5) contains 0.20% w/v Bisacodyl EPCRS in acetone Dried plate examined under UV-light (254 nm) Any secondary spot obtained with soln. (1) is not more intense than spot with soln. (3) and not more than one spot is more intense than spot with sol. (4)... 

D. Mandler and 1. Willner, Photosensitized NAD(P)H regeneration systems application in the reduction of butan-2-one, pyruvic, and acetoacetic acids and in the reductive amination of pyruvic and oxoglutaric acids to amino acids,... 

An acid-rhenium catalyst mixture acts on ( )-4-(4-hydroxyphenyl)butan-2-one oxime (44) to produce a high yield of the spiro compound (45), which then rearranges to the substituted quinoline (46)." ° The Beckmann rearrangement product (47)... 

The next example deals with an effect of ferrous chloride addition (Galli and Gentili 1993). Phenyl iodide reacts with the potassium derivative of l,l-dimethyl-butan-2-one (pinacolin) in DMSO according to the following equations ... 

Eluorine-18 was also used as a tool for the study of the base promoted HF elimination from 4-fluoro-4-(4 -nitrophenyl)butan-2-one [62] (Scheme 3). The F KIEs values were respectively 1.0037,1.0047 and 1.0013 with formate, acetate or imidazole used as the base. The size of the fluorine KIEs corresponds to 5 -15 % of the estimated maximum for complete C-F bond breakage and is consistent with a postulated ElcB-E2 Hke or ElcBjp mechanism. 

An alternative approach to mixed aldol reactions, and the one usually preferred, is to carry out a two-stage process, forming the enolate anion first using a strong base like EDA (see Section 10.2). The first step is essentially irreversible, and the electrophile is then added in the second step. An aldol reaction between butan-2-one and acetaldehyde exemplifies this approach. Note also that the large base EDA selectively removes a proton from the least-hindered position, again restricting possible combinations (see Section 10.2). 

In the Madera cockroach, Leucophaea maderae, male calling behavior involves the release of a sex pheromone from the abdominal sternal glands. The extracts of sternal glands attracted conspecific females over a distance and the compounds responsible were identified as hydroxy-3-butan-2-one, (27 , 37 )-butanediol, senecioic acid and ( )-2-octenoic acid. The same components are also present in the male tergal glands. 

C12H23N5O2 3- [2-(2-Hydroxyimino-l-methylpropylideneamino)-ethylamino]-ethylimino -butan-2-one oxime Spectrophotometric Cu 110... 

Beach JV, Shea KJ. Designed catalysts. A synthetic network pol3mier that catalyzes the dehy-drofluorination of 4-fluoro-(p-nitrophenyl)butan-2-one. J Am Chem Soc 1994 116 379-380. 

Butan-2-one, 1-acetoxy Sd (roasted) Butan-2-one, 4-(2 -furyl) Sd (roasted) a063 Butan-2-one, 4-(2 -furyl-5 -methyl) Sd... 

Sulfation of H-Thr-OH was carried out as described for H-Ser(S03K)-OH after 1 h the mixture was poured into butan-2-one (400 mL). The final product was precipitated from the aqueous soln with Et20/ butan-2-one (1 1) to give the product as its monohydrate yield (40%) [a]D18 -20.6 (c 9.7, H20). 

Raspberry ketone [4-(4 -hydroxyphenyl)-butan-2-one], the impact compound found in raspberries, can be obtained by enzymatic reactions The first step is the /i-glucosidase-catalysed hydrolysis of the naturally occurring betu-loside to betuligenol. The latter can be transformed into raspberry ketone by microbial alcohol dehydrogenase (Scheme 22.2) [56]. 

---