Conversion of penicillin to cephalosporin via a double sulfoxide rearrangement

Spry, Douglas O.

doi:10.1021/ja00719a054

Cited by 42 publications

(14 citation statements)

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“…Therefore 2 is assigned the S configuration and 3 the R configuration. Our figures are in good agreement with the ASIS values obtained for the epiphthalimidopenicillin sulfoxides 5 and 6.3 Sulfoxide bond chemical shift perturbations have also been useful in assigning configuration of sulfoxides.3 •8•11•12 Table III summarizes the chemical shift changes in 6-epiphenoxymethyl- (7) and phenoxymethylpenicillin benzyl ester (8) upon oxidation to their corresponding sulfoxides. The data show that the sulfoxide bond in sulfoxides 1 and 2 exerts shielding effects on H5 and the 2a methyl group and exerts deshielding effects on H3, He, and the 20-methyl group.…”

supporting

confidence: 82%

“…Ester (7) with Ozone. The 6-epiphenoxymethylpenicillin benzyl ester (7, 660.0 mg, 1.5 mmol) was oxidized with ozone as described for 8 under A, yielding 386.0 mg (56%) of amorphous solid, which contained the two sulfoxides 2 and 3 in a ratio of about 1:1 (nmr).…”

Section: -Epiphenoxymethylpenicillin (Fi)-sulfoxide Benzyl Ester (3) ...mentioning

confidence: 99%

“…(R) -and (S)-sulfoxides 5 and 6 in a ratio of 1:4, the application of the same method to 6-epiphenoxymethylpenicillin benzyl ester (7) yielded only the 6-epi (S)-sulfoxide2 2. The 6-epiphenoxymethylpenicillin (fi)-sulfoxide benzyl ester (3), however could be prepared by oxidation of 6-epiphenoxymethylpenicillin benzyl ester (7) with iodobenzene dichloride.4•5 Surprisingly no corresponding 6-epi (S) -sulfoxide 2 was formed in this reaction, while oxidation of phenoxymethylpenicillin benzyl ester (8) with iodobenzene dichloride afforded a mixture of the (S)-and (R) -sulfoxides 1 and 9 in a ratio of approximately 1:4.…”

mentioning

confidence: 94%

“…In 6-epiphenoxymethylpenicillin (R)-sulfoxide benzyl ester (3) positive effects (in CDCI3 and CeDe) were observed between the 2/3methyl group (1.46, 0.89 ppm) and the H3 signal (4.52, 4.33 ppm) (18 and 16%) and between the 2a-methyl group (1.34, 1.19 ppm) and the H5 (4.79, 4.93 ppm) (10 and 8%). Finally, 6-epiphenoxymethylpenicillin benzyl ester (7) gave NOE effects (in CDCI3 and CeDe) between H3 (4.55, 4.50 ppm) and the 2a-methyl group (1.40, 1.15 ppm) (7 and 9%) and the 2/S-methyl group (1.60, 1.22 ppm) (17 and 20%).…”

mentioning

confidence: 99%

“…With ozone as oxidant6•7 in acetone-water (3:2) both phenoxymethyl - (8) and 6-epiphenoxymethylpenicillin benzyl ester (7) afforded a mixture of the corresponding (S)-and (fi)-sulfoxides in a ratio of about 1:1. In the former mixture the two sulfoxides 1 and 9 were isolated by column chromatography, while in the latter mixture 6-epi (S)-sulfoxide 2 was separated from 6-epi (fi)-sulfoxide 3 by fractional crystallization from dry benzene, because the two isomers presented the same R¡ values in our chromatographic systems.…”

mentioning

confidence: 99%

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Configuration of phenoxymethyl- and 6-epi phenoxymethylpenicillin sulfoxides

Vlietinck¹,

Roets²,

Vanderhaeghe³

1974

J. Org. Chem.

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Phenoxymethyl-(8) and 6-epiphenoxymethylpenicillin benzyl ester (7) and their corresponding (S)-and (R)sulfoxides were studied. The methyl signals in the nmr spectra of these compounds were assigned by nuclear Overhauser effects, and the configuration was determined by aromatic solvent induced shifts and by sulfoxide bond chemical shift perturbations. Finally, deuterium incorporation was studied in the isomerization of phenoxymethyl-( 10) and 6-epiphenoxymethylpenicillin (fl)-sulfoxide benzyl ester (3) to their corresponding (S)-

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supporting

confidence: 82%

Section: -Epiphenoxymethylpenicillin (Fi)-sulfoxide Benzyl Ester (3) ...mentioning

confidence: 99%

mentioning

confidence: 94%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Configuration of phenoxymethyl- and 6-epi phenoxymethylpenicillin sulfoxides

Vlietinck¹,

Roets²,

Vanderhaeghe³

1974

J. Org. Chem.

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The P ummerer Reaction of Sulfinyl Compounds

Lucchi

Miotti²,

Modena³

1991

Organic Reactions

102

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The Pummerer reaction involves the formation of an α‐functionalized sulfide from a sulfoxide bearing at least one α‐hydrogen atom. The reaction can also be described as an internal redox process where the SX group is reduced and the α carbon is oxidized. The first report by Pummerer on the reaction which now bears his name appeared in 1909 and described the formation of thiophenol and glyoxylic acid on heating phenylsulfinylacetic acid with mineral acids. The products Pummerer observed resulted from hydrolysis of the initially formed α‐substituted sulfides, which are the typical products of the reaction. The term “Pummerer reaction” was later extended to the reaction of sulfoxides with acid anhydrides. Selenium and nitrogen analogs undergo similar reactions. The former is known as the seleno–Pummerer reaction, and the latter is usually referred to as the Polonovski reaction. The sila–Pummerer reaction, which is also discussed in this chapter, is the rearrangement of sulfoxides bearing a silyl group on the α carbon. From a mechanistic point of view there are many other reactions, sometimes given specific names, such as the Sommelet–Hauser, Stevens, and Vilsmeier rearrangements, that appear to resemble the Pummerer reaction. Reactions in which the sulfoxide group acts as an oxidant in an intermolecular redox process have characteristics similar to the typical Pummerer reaction. The α‐halogenation of sulfides, in which the sulfide sulfur may first be oxidized to a halosulfonium salt that rearranges to the final product, is formally similar to the Pummerer reaction. For the sake of clarity and to be as exhaustive as possible, we have limited the scope of this chapter to the restrictive definition.

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The Total Synthesis of Antibiotics

Johnson

1973

Total Synthesis of Natural Products

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Conversion of penicillin to cephalosporin via a double sulfoxide rearrangement

Cited by 42 publications

References 0 publications

Configuration of phenoxymethyl- and 6-epi phenoxymethylpenicillin sulfoxides

Configuration of phenoxymethyl- and 6-epi phenoxymethylpenicillin sulfoxides

The P ummerer Reaction of Sulfinyl Compounds

The Total Synthesis of Antibiotics

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