Pyrrolidine acetylation

Acetic anhydride, pyridine, pyrrolidine, acetyl or propionyl chloride, sodium borohydide, dioxane, and 1-methylnaphthalene are available from a number of suppliers, including Aldrich Chemical Co. 

Pyrrolidine Acetyl chloride A/-Acetylpyrrolidine (79%) Pyrrolidine hydrochloride... 

The reaction of ketene with the enamine (113) is reported (88) to give l-morpholino-2-acetyl-l-cyclohexene i.e., the enamino ketone expected from acylation of (113). The pyrrolidine enamine (28), however, has been shown to react (73) with excess ketene to give the a-pyrone (124). On the... 

At higher temperatures the mixture of 10 and methyl vinyl ketone yields the 1,4-carbocyclic compound as described previously. Methyl isopropenyl ketone (5), ethyl acetylacrylate (d), 2-cyclohexenone (21), and 1-acetyl-1-cyclohexene (22) also undergo this type of cyclization reaction with enamines at higher temperatures. This cycloalkylation reaction occurs with enamines made of strongly basic amines such as pyrrolidine, but the less reactive morpholine enamine combines with methyl vinyl ketone to give only a simple alkylated product (7). Chlorovinyl ketones yield pyrans when allowed to react with the enamines of either alicyclic ketones or aldehydes (23). 

Acylation of the vinylogous pyrrolidine amide of dimedone with acetic anhydride or acetyl chloride led (possibly indirectly) to the carbon acylation product, whereas trichloroacetyl chloride gave rise to products derived from attack of chloride at the oxygenated double bond position in an initial 0-acylation product (401-404). 

I liickel 4/r + 2 rule and. 528-529 industrial synthesis of, 946 Pyrrolidine, electrostatic potential map of. 947 structure of, 918 Pyrrolysine, structure of, 1020 Pyruvate, acetyl CoA from. 

Use of the valine derived (4S )-3-acetyl-4-isopropyl-1,3-oxazolidine (8)92, the C2-symmetric reagents (2.5,55)-l-acetyl-2,5-bissubstituted pyrrolidine 994, or the doubly deprotonated acetyl urea /V-acetyl- V..V -bis[(.S)-l-phcnylethyl]urea (10), also does not lead to sufficient induced stereoselectivity combined with acceptable chemical yield. When the acetyl urea enolate is reacted with aliphatic and aromatic aldehydes, the diastereomeric adducts (ratios ranging from 1 1 to 3 1) may be separated by column chromatography to give ultimately both enantiomers of the 3-hydroxy acids in 99% ee110. 

Because activated 4-0-trimethylsilylated-2, 3, 5 -0-acyluridines such as 3 are also obtained as reactive intermediates in the Friedel-Crafts-catalyzed silyl-Hilbert-Johnson reaction [59, 59 a] of persilylated uracils or 6-azauracils such as 227 with sugars such as l-0-acetyl-2,3,5-tri-0-benzoyl-/9-D-ribofuranose 228 in the presence of SnCl4, treatment of the reactive intermediate 229 with a large excess of pyrrolidine neutralizes the SnCLi. used and aminates 229 to afford the protected 6-aza-cytidine 230, although in 57% yield only [49, 59] (Scheme 4.20). 

A propoxyphene-like analgesic which obeys the empirical morphine rule is pyrroliphene (101). A Mannich reaction involving pyrrolidine, formaldehyde and propiophenone gave amino ketone 99, which was converted to tertiary carbinol 100 by reaction with benzyl magnesium chloride reaction with acetyl... 

In a subsequent study, Schnitzer and Spiteller [15] hydrolyzed each fraction with 2 M H2S04. After neutralization of the soluble materials, the latter were reduced with NaBH4 and then acetylated. The resulting acetates were analyzed by capillary gas chromatography/mass spectrometry, and identified by comparing their mass spectra with those of reference compounds of known structures and with literature data. Eighteen N-heterocyclics were identified. These compounds induded hydroxy-and oxy-indoles, quinolines, isoquinolines, aminobenzofurans, piperidines, pyrro-lines, and pyrrolidines. In addition, a number of benzylamines and nitriles were also identified. It is noteworthy that the N heterocyclics were isolated and identified without the use of pyrolysis. 

Cefpirome Cefpirome, 6R-[6a,l (7)] -l-[(7- [(2-amino-4-thiazolyl)-(methoximino) acetyl]amino -2-carboxy-8-oxo-5-thia-l-azabicyclo[4.2.0]oct-2-en-3-yl)methyl-l-methyl]pyrrolidine chloride (32.1.2.100), is also synthesized by methods described for synthesizing third-generation cephalosporins, in particular, ceftazidime (32.1.2.82) [177,178]. 

The (—)-anisomycin work is presented in Scheme 35. Its key step centered around the formation of a pyrrolidine ring that possessed all three of the asymmetric centers present in the target this was done by nucleophilic displacement of a 3-tosyloxy function in an appropriately functionalized 6-amino-6-deoxy-p-i.-talose derivative, whose 1,2-diol was later released and oxidatively cleaved with sodium periodate. Grignard coupling, O-acetylation, and catalytic hydrogenation then furnished the desired natural-product target. 

L-metilionine to -adenosylmethionine. In this process a positively charged sulphur is produced and facilitates the nucleophilic reaction. By the activity of diamine oxidase, the A -methyl-A -pyrrolinium cation is formed and after that the first alkaloid, hygrine. From hygrine, by way of acetyl CoA, hydrolysis and intramolecular Mannich reactions, other pyrrolidine and tropane alkaloids are synthesized cuscohygrine, hyoscyamine or tropinone, tropine and cocaine. The Mannich reaction involves the combination of an amine, an aldehyde or a ketone with a nucleophilic carbon. This reaction is typical in alkaloid synthesis, and can be written as follows ... 

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