Cyclization of cysteinylglycine sulfoxides under Pummerer reaction conditions

1979 ◽  
Vol 57 (18) ◽  
pp. 2412-2425 ◽  
Author(s):  
Saul Wolfe ◽  
Peter Michael Kazmaier ◽  
Hillar Auksi
Keyword(s):  
Acetic Anhydride ◽  
Trifluoroacetic Acid ◽  
Carboxyl Group ◽  
Reaction Conditions ◽  
Pummerer Reaction ◽  
Peptide Cyclization

A number of sulfoxides derived from 3-benzylthiopropionic acid, S-benzylcysteine, and S-phenylcystelne have been synthesized and exposed to typical Pummerer reaction conditions. Cyclization of the S-benzyl sulfoxides to six-membered or seven-membered heterocyclic rings (1,3-thiazin-4-ones and 1,3,6-oxathiazepines) is observed only in acetic anhydride solvent and only after conversion of the carboxyl group to an amide or peptide. Cyclization of S-phenylcysteinyl amides to β-lactams could not be achieved. The thiazolidine isomers of the six- and seven-membered rings have been synthesized and found not to be intermediates in the acetic anhydride reactions. The thiazolidines do rearrange to the six- and (or) seven-membered rings in anhydrous trifluoroacetic acid solvent. S-Benzylphthalimidocysteinylglycine sulfoxide, a 3:2 mixture of epimers at sulfur, affords a 3:2 mixture of isomeric thiazinones. A mechanism for these cyclizations is proposed, and it is suggested that the configuration at sulfur controls the configuration at the new asymmetric centre in the product.

On the relationships between 18O-transfer, diastereotopic selectivity, and asymmetric induction in an intramolecular Pummerer reaction

1979 ◽  
Vol 57 (18) ◽  
pp. 2404-2411 ◽  
Author(s):  
Saul Wolfe ◽  
Peter Michael Kazmaier ◽  
Hillar Auksi
Keyword(s):  
Acetic Anhydride ◽  
Opposite Sign ◽  
Optically Active ◽  
Asymmetric Induction ◽  
Carboxyl Group ◽  
Initial Attack ◽  
Deuterium Labelling ◽  
Pummerer Reaction ◽  
Reaction Proceeds ◽  
The Relationship

The cyclization of benzyl 2-carboxyphenyl sulfoxide (1) to 2-benzylbenzoxathiane-6-one (2) has been examined by a combination of 18O-labelling of the sulfoxide oxygen, stereoselective deuterium labelling in the benzylic position, and the use of optically active compounds. With dicyclohexylcarbodiimide (DCC) as the cyclizing agent, the reaction proceeds with 55.8% retention of the sulfoxide oxygen, 57.8% preference for abstraction of one of the diastereotopic methylene protons, and it produces a 61.4/38.6 mixture of enantiomers. It is proposed that all three experimental observables are controlled by the competition between initial attack of the DCC upon the sulfoxide oxygen and upon the carboxyl group, and a mechanism is proposed for the reaction which clarifies the relationship between these observables. In agreement with earlier work by Stridsberg and Allenmark, DCC affords 2 having the opposite sign of rotation from 1, and acetic anhydride affords 2 having the same sign of rotation as 1. Asymmetric induction in the latter reaction is significantly less than with DCC because of competing epimerization at sulfur, but the origin of the differences in the sign of rotation of 2 under the different conditions has been clarified by the finding that there is less than 40% retention of the sulfoxide oxygen with acetic anhydride as the reagent.

scholarly journals Frontispiece: A Tandem In Situ Peptide Cyclization through Trifluoroacetic Acid Cleavage

2014 ◽  
Vol 53 (36) ◽  
pp. n/a-n/a
Author(s):  
Koushik Chandra ◽  
Tapta Kanchan Roy ◽  
Deborah E. Shalev ◽  
Abraham Loyter ◽  
Chaim Gilon ◽  
...  
Keyword(s):  
Trifluoroacetic Acid ◽  
Peptide Cyclization ◽  
Acid Cleavage

Medium-sized cyclophanes, part 59:1 Nitration of [3.3]- and [3.3.3]metacyclophanes — Through-space electronic interactions between two or three benzene rings

2002 ◽  
Vol 80 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Takehiko Yamato ◽  
Koji Tsuchihashi ◽  
Noriko Nakamura ◽  
Mai Hirahara ◽  
Hirohisa Tsuzuki
Keyword(s):  
Acetic Anhydride ◽  
Electronic Interaction ◽  
Reaction Conditions ◽  
Tert Butyl ◽  
Mixed Acid ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Starting Compound ◽  
Nitration Product ◽  
Fuming Nitric Acid

The two tert-butyl groups of anti-6,15-di-tert-butyl-9,18-dimethoxy[3.3]metacyclophane (anti-4) are both ipso-nitrated even under mild reaction conditions such as copper(II) nitrate in an acetic anhydride solution because of the decreased deactivation of the second aromatic ring by the introduced nitro group. On the other hand, anti-5,13-di-tert-butyl-8,16-dimethoxy[2.2]metacyclophane (anti-1) undergoes replacement of only one tert-butyl group under the same reaction conditions. The higher yields of the twofold ipso-nitration product anti-7 were obtained in nitration of anti-4 with fuming nitric acid or mixed acid (HNO3–H2SO4). Thus, the number of ipso-nitrations at the tert-butyl groups of anti-4 was strongly affected by the reactivity of the nitration reagent. Nitration of the corresponding syn-conformer syn-4 with copper(II) nitrate in an acetic anhydride solution, however, led only to the recovery of the starting compound. The presently developed procedure was further applied to the direct removal of the tert-butyl group by electrophilic substitution of the larger-sized ring macrocyclic metacyclophanes, cone- and partial-cone-tri-tert-butyl[3.3.3]metacyclophanes 11.Key words: [3n]metacyclophanes, conformation, ipso-nitration, through-space electronic interaction, crystal structure.

C-Formylation of Some 2(3H)-Benzazolones and 2H-1,4-Benzoxazin-3(4H)-one

1997 ◽  
Vol 62 (3) ◽  
pp. 494-497 ◽  
Author(s):  
Ognyan I. Petrov ◽  
Veneta B. Kalcheva ◽  
Antonina Ts. Antonova
Keyword(s):  
Methyl Ether ◽  
Trifluoroacetic Acid ◽  
Reaction Conditions

The C-formylation of 1,3-dimethyl-2(3H)-benzimidazolone and 4-methyl-2H-1,4-benzoxazin-3(4H)-one was performed using 1,1-dichloromethyl methyl ether at the Friedel-Crafts reaction conditions. The formylation of 3-methyl-2(3H)-benzoxa- and -thiazolone at the 6-position was carried out by modified Duff's method with hexamethylenetetramine in trifluoroacetic acid.

Base-catalyzed Degradations of Carbohydrates. III. Formation of a Novel Perester from 1-O-Acetyl-3-deoxy-2,4,6-tri-O-methyl-α-D-erytho-hex-2-enopyranose

1973 ◽  
Vol 51 (3) ◽  
pp. 388-393 ◽  
Author(s):  
G. O. Aspinall ◽  
R. R. King ◽  
Zofia Pawlak
Keyword(s):  
Acetic Anhydride ◽  
Spectral Data ◽  
Trifluoroacetic Acid ◽  
Oxidative Degradation ◽  
Chemical Degradation ◽  
Reductive Decomposition

1-O-Acetyl-3-deoxy-2,4,6-tri-O-methyl-α-D-erythro-hex-2-enopyranose (1) reacts with m-chloroperbenzoic acid to give a novel perester, which has been assigned the structure 1,2-O-(1′-m-chloroperbenzoyl-oxyethylidene)-2-methoxy-4,6-di-O-methyl-α-D-glucopyranose (2), on the basis of spectral data and chemical degradation. The perester 2 and the derived acetate 3 undergo oxidative degradation on treatment with trifluoroacetic acid to give 3,5-di-O-methyl- (4) and 2-O-acetyl-3,5-di-O-methyl-D-arabinonolactone (5), respectively. Reductive decomposition of the acetylated perester 3 yields 1,3-di-O-acetyl-4,6-di-O-methyl-α-D-arabino-hexopyranosulose (6), which, on treatment with acetic anhydride in pyridine, gives successively 1,2,3-tri-O-acetyl-4,6-di-O-methyl-α-D-erythro-hex-2-enopyranose (7), 2-O-acetyl-1-deoxy-4,6-di-O-methyl-α-D-erythro-hex-1-enopyranose-3-ulose (8), and 5-acetoxy-2-(methoxy-methyl)-4H-pyran-4-one (9).

β-Oxo-sulfoxide rearrangements under sila-Pummerer reaction conditions

1992 ◽  
Vol 33 (41) ◽  
pp. 6143-6146 ◽  
Author(s):  
Martial Dardaine ◽  
Angèle Chiaroni ◽  
Claude Riche ◽  
Nicole Langlois
Keyword(s):  
Reaction Conditions ◽  
Pummerer Reaction

Pummerer Reaction of Sulfoxides in Acetic Anhydride Catalyzed by Al-MCM-41

2016 ◽  
Vol 45 (1) ◽  
pp. 16-18 ◽  
Author(s):  
Suguru Ito ◽  
Yoshihiro Kubota ◽  
Masatoshi Asami
Keyword(s):  
Acetic Anhydride ◽  
Pummerer Reaction ◽  
Mcm 41
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