Total Synthesis of Racemic and Optically Active Sarkomycin

Mikoajczyk, Marian; urawiski, Remigiusz; Kie?basi?;ski, Piotr; Wieczorek, M. W.; B?aszczyk, Jaros?aw; Majzner, Wiesław R.

doi:10.1055/s-1997-1193

Cited by 19 publications

(10 citation statements)

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“…Particularly interesting are cyclopentenone derivatives, as the resulting adducts possess substructures present in a large number of natural products of interest [117] including jasmonoids, and prostaglandins, and cyclopentenoid antibiotics, such as methylenomycin A, [118] methylenomycin B, xanthocydin, [119] cyclosarkomycin, [120] and sarkomycin. [121] Additionally, compounds 221-227 have the practical advantage of a stable C=C configuration, which simplifies their synthesis and avoid considering eventual E/Z isomerization (Scheme 39). Pyrrolidine-derived formaldehyde hydrazone 51k (R = H) [91] showed a much higher reactivity than 51a and when treated with compounds 221, 222, 223, and 224 the reaction proceeded spontaneously to afford corresponding adducts 228-230k and 233k in moderate-to-good yields (50-85 %).…”

Section: Addition To Activated Cyclic Alkenesmentioning

confidence: 99%

Aldehyde N,N‐Dialkylhydrazones as Neutral Acyl Anion Equivalents: Umpolung of the Imine Reactivity

et al. 2007

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The isoelectronic replacement of the α‐carbon of enamines by nitrogen leads to the corresponding hydrazones, and thus, they can be termed “aza‐enamines”. Hence, aldehyde N,N‐dialkylhydrazones enable analogous electrophilic substitutions at the imine carbon that corresponds to the β‐carbon of enamines. In addition, after hydrolysis of the product hydrazones to the parent ketones or aldehydes, these reactions constitute an umpolung of the classical carbonyl reactivity and overall a nucleophilic acylation or formylation. This review covers the aza‐enamine chemistry from its very beginning in the late 1960s up to this year. In the first part, reactions of aromatic, aliphatic, and heterocyclic aldehyde N,N‐dialkylhydrazones with highly reactive substrates such as the Vilsmeier and Mannich reagents, sulfonyl isocyanates, perfluoroacetic anhydride, and inorganic electrophiles such as halogens and phosphorus tribromide are described. The hydrazones of α,β‐unsaturated aldehydes react as vinylogous aza‐enamines at the terminal carbon providing unsaturated aldehydes. As electron‐rich dienes and dienophiles, they also form Diels–Alder adducts and thus interesting N‐heterocycles. The second part covers carbon–carbon bond formations of the sterically less‐demanding formaldehyde N,N‐dialkylhydrazones with synthetically very useful electrophiles such as various Michael acceptors and carbonyl compounds. Formaldehyde SAMP‐hydrazone and related derivatives generally give excellent asymmetric inductions. Finally, first organocatalytic versions of the aza‐enamine chemistry are presented. In summary, the rich chemistry of aldehyde N,N‐dialkylhydrazones as neutral acyl anion, formyl anion, and cyanide equivalents is demonstrated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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Section: Addition To Activated Cyclic Alkenesmentioning

confidence: 99%

Aldehyde N,N‐Dialkylhydrazones as Neutral Acyl Anion Equivalents: Umpolung of the Imine Reactivity

et al. 2007

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“…Moreover, we decided to utilize the intramolecular carbenoid cyclization for the construction of the cyclopentanone ring. Our total synthesis of (Ϯ)-5 is shown in Scheme 14 [17].…”

Section: Synthesis Of Racemic and Optically Active Sarkomycinmentioning

confidence: 99%

New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins

Mikołajczyk¹,

Mikina²,

Żurawiński³

1999

Pure and Applied Chemistry

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This account outlines the results obtained in the author's laboratory on the application of phosphonate reagents in the synthesis of biologically active cyclopentanones and cyclopentenones. The synthesis and reactivity of 3-phosphorylmethyl-cycloalkenones is discussed as a platform for developing the first synthesis of enantiomeric isoterreins as well as the synthesis of racemic and optically active prostaglandins B 1␣ . A different strategy for the total synthesis of racemic and enantiomeric forms of sarkomycin and rosaprostol is described which involves in a key step intramolecular carbenoid cyclization of the corresponding ␣-diazo-␤-ketophosphonates.

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“…Some of the syntheses addressed the racemic mixture and involve a relatively large number of steps . In other cases, the desired enantiopurity was obtained via (a) kinetic resolution, (b) the chiral auxiliary approach, or (c) classical racemic resolution . However, most of these processes gave low overall yields.…”

mentioning

confidence: 99%

“…8 In other cases, the desired enantiopurity was obtained via (a) kinetic resolution, 9 (b) the chiral auxiliary approach, 10 or (c) classical racemic resolution. 11 However, most of these processes gave low overall yields. A recent report by Von Zezschwitz and co-workers 12 was the first to use asymmetric catalysis.…”

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confidence: 99%

Total Synthesis of (R)-Sarkomycin Methyl Ester via Regioselective Intermolecular Pauson–Khand Reaction and Iridium-Catalyzed Asymmetric Isomerization

et al. 2018

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A new five-step enantioselective synthesis of ( R)-sarkomycin methyl ester is described. The cyclopentane scaffold was built by a regioselective intermolecular Pauson-Khand reaction. Enantioselectivity was introduced by a novel Ir-catalyzed isomerization reaction. The last steps involved a catalytic hydrogenation of the exocylic double bond, followed by the deprotection and elimination of the amino group. This route is the shortest enantioselective synthesis of this antibiotic reported to date.

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Total Synthesis of Racemic and Optically Active Sarkomycin

Cited by 19 publications

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Aldehyde N,N‐Dialkylhydrazones as Neutral Acyl Anion Equivalents: Umpolung of the Imine Reactivity

Aldehyde N,N‐Dialkylhydrazones as Neutral Acyl Anion Equivalents: Umpolung of the Imine Reactivity

New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins

Total Synthesis of (R)-Sarkomycin Methyl Ester via Regioselective Intermolecular Pauson–Khand Reaction and Iridium-Catalyzed Asymmetric Isomerization

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