The organoselenium-mediated reduction of α,β-epoxy ketones, α,β-epoxy esters, and their congeners to β-hydroxy carbonyl compounds: Novel methodologies for the synthesis of aldols and their analogues

Miyashita, Masaaki; Suzuki, Toshio; Hoshino, M.; Yoshikoshi, Akira

doi:10.1016/s0040-4020(97)00781-3

Cited by 119 publications

(74 citation statements)

References 38 publications

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“…Diol 3 is actually accessible either by keto-reduction and debenzylation 10 of ethyl 5-benzyloxy-3-oxopentanoate, 12 The first approach allowed the synthesis of 2 also in asymmetric fashion, but required the preparation of precursor and high pressure apparatus, while the second method of synthesis demanded a noncommercial reagent and a specific reducing agent.…”

Section: Resultsmentioning

confidence: 99%

Efficient synthesis of 1,3,5-oxygenated synthons from dimethyl 3-oxoglutarate: first use of borane-dimethyl sulfide complex as a regioselective reducing agent of 3-oxygenated glutarate derivatives

Riatto¹,

Carneiro²,

Carvalho³

et al. 2011

J. Braz. Chem. Soc.

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A redução seletiva do 3-oxoglutarato de dimetila foi realizada em vários níveis. A redução quimiosseletiva da carbonila cetônica com boridreto de sódio é descrita em alto rendimento, fornecendo o 3-hidroxiglutarato de dimetila. Quando o complexo borana-dimetil sulfeto (BMS) foi empregado como agente redutor, um diol ou um triol puderam ser obtidos, respectivamente, a partir do 3-hidróxi-ou do 3-oxoglutarato, permitindo a síntese de compostos 1,3,5-oxigenados prática e eficientemente.The selective reduction of dimethyl 3-oxoglutarate was accomplished in different levels. A high yielding sodium borohydride reduction of the keto group is fully described leading to dimethyl 3-hydroxyglutarate. When borane-dimethyl sulfide (BMS) complex was used, a diol or a triol compound can be obtained by selective or total reduction of 3-hydroxy-or 3-oxoglutarate, respectively, allowing an efficient and practical route to 1,3,5-oxygenated compounds.

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Section: Resultsmentioning

confidence: 99%

Efficient synthesis of 1,3,5-oxygenated synthons from dimethyl 3-oxoglutarate: first use of borane-dimethyl sulfide complex as a regioselective reducing agent of 3-oxygenated glutarate derivatives

Riatto¹,

Carneiro²,

Carvalho³

et al. 2011

J. Braz. Chem. Soc.

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“…Then, 49 was converted to amino acetal 50 by a three-step reaction sequence: 1) oxidation with mCPBA in CH 2 Cl 2 ; 2) hydrogenation of the azido group over PtO 2 in MeOH in the presence of Boc 2 O; 3) protection of the hydroxyl and the amino groups by treatment with 2-methoxypropene and pyridinium m-nitrobenzenesulfonate in DMF, in 91 % overall yield. Treatment of the epoxides 50 with Na- [35,36] in EtOH at 80 8C, followed by oxidation of the resulting hydroxy selenides with H 2 O 2 in a one-pot operation, furnished allyl alcohol 51 in 93 % yield. Finally, ozonolysis of 51 in MeOH-CH 2 Cl 2 in the presence of NaHCO 3 produced the amino-alcohol segment 52 in 92 % yield.…”

Section: Resultsmentioning

confidence: 99%

Synthetic Studies of the Zoanthamine Alkaloids: The Total Syntheses of Norzoanthamine and Zoanthamine

Yoshimura

Sasaki

Hattori

et al. 2009

Chemistry A European J

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The zoanthamine alkaloids, a type of heptacyclic marine alkaloid isolated from colonial zoanthids of the genus Zoanthus sp., have distinctive biological and pharmacological properties in addition to their unique chemical structures with stereochemical complexity. Namely, norzoanthamine (1) can suppress the loss of bone weight and strength in ovariectomized mice and has been expected as a promising candidate for a new type of antiosteoporotic drug, while zoanthamine (2) has exhibited potent inhibitory activity toward phorbol myristate-induced inflammation in addition to powerful analgesic effects. Recently, norzoanthamine derivatives were demonstrated to inhibit strongly the growth of P-388 murine leukemia cell lines, in addition to their potent antiplatelet activities on human platelet aggregation. Their distinctive biological properties, combined with novel chemical structures, make this family of alkaloids extremely attractive targets for chemical synthesis. However, the chemical synthesis of the zoanthamine alkaloids has been impeded owing to their densely functionalized complex stereostructures. In this paper, we report the first and highly efficient total syntheses of norzoanthamine (1) and zoanthamine (2) in full detail, which involve stereoselective synthesis of the requisite triene (18) for an intramolecular Diels-Alder reaction via the sequential three-component coupling reactions, the key intramolecular Diels-Alder reaction, and subsequent crucial bis-aminoacetalization as the key steps. Ultimately, we achieved the total synthesis of norzoanthamine (1) in 41 steps with an overall yield of 3.5 % (an average of 92 % yield each step) and that of zoanthamine (2) in 43 steps with an overall yield of 2.2 % (an average of 91 % yield each step) starting from (R)-5-methylcyclohexenone (3), respectively.

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“…This epoxide rapidly decomposed on silica gel, and it was very difficult to obtain it in higher yields with satisfactory purity. Its regioselective opening was accomplished by using the organoselenium reagent developed by Miyashita 45 to limit dehydration of the β-hydroxyaldehyde. Treatment of 24 with the phenylseleno(triethyl)borate complex, prepared by reduction of (PhSe) 2 with NaBH 4 in EtOH, gave the five-membered cyclization product 25 (46%) (Scheme 6).…”

Section: Methodsmentioning

confidence: 99%

Studies toward the synthesis of angularly-oxygenated angucyclines antibiotics

Lebrasseur¹,

Fan²,

Quideau

2004

Arkivoc

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The [bis(trifluoroacetoxy)]iodobenzene-mediated oxidative dearomatization of 2-alkoxyarenols, followed in situ by trapping of the resulting arenoxenium ions by soft external carbon-based nucleophiles, constitutes a rapid access to highly functionalized naphthoid cyclohexa-2,4-dienones. These synthons can serve as valuable intermediates in the construction of the angularly-oxygenated benz [a]anthraquinone ABCD tetracyclic ring system of aquayamycin-like angucyclinones. This methodology so far has led to the elaboration of five-membered ring analogues of the ABC tricyclic unit of these natural products.

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The organoselenium-mediated reduction of α,β-epoxy ketones, α,β-epoxy esters, and their congeners to β-hydroxy carbonyl compounds: Novel methodologies for the synthesis of aldols and their analogues

Cited by 119 publications

References 38 publications

Efficient synthesis of 1,3,5-oxygenated synthons from dimethyl 3-oxoglutarate: first use of borane-dimethyl sulfide complex as a regioselective reducing agent of 3-oxygenated glutarate derivatives

Efficient synthesis of 1,3,5-oxygenated synthons from dimethyl 3-oxoglutarate: first use of borane-dimethyl sulfide complex as a regioselective reducing agent of 3-oxygenated glutarate derivatives

Synthetic Studies of the Zoanthamine Alkaloids: The Total Syntheses of Norzoanthamine and Zoanthamine

Studies toward the synthesis of angularly-oxygenated angucyclines antibiotics

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