One-Pot Cyclizations of Dilithiated Oximes and Hydrazones with Epibromohydrin. Efficient Synthesis of 6-Hydroxymethyl-5,6-dihydro-4<i>H</i>-1,2-oxazines and Oxazolo[3,4-<i>b</i>]pyridazin-7-ones

Dang, Tuan Thanh; Albrecht, Uwe; Gerwien, Katrin; Siebert, Melanie; Langer, Peter

doi:10.1021/jo052329e

Cited by 20 publications

(12 citation statements)

References 34 publications

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“…Similar rearrangement has been recently described by the Langer group in a series of 3-aryl-6-(hydroxymethyl)-substituted SCOE 191 (Scheme ) . These oxime ethers upon the action of phosphorus tribromide are converted to tetrahydrofurans 192 in poor yields.…”

Section: Chemical Properties Of Scoesupporting

confidence: 60%

“…Langer and co-workers , reported that anions of oximes 49 obtained in situ from the dilithiated derivatives of oximes 51 and epibromohydrine (Scheme , eq 2) undergo cyclization with the participation of the epoxide group and the oxygen atom of the oximino group, giving rise to dihydrooxazines 50 in moderate to good yields. If substituent R 1 ≠ H, the products are obtained as a mixture of diastereomers (dr ∼ 1:1) …”

Section: Synthesis Of Six-membered Cyclic Oxime Ethers 1 Andmentioning

confidence: 99%

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Chemistry of Six-Membered Cyclic Oxime Ethers. Application in the Synthesis of Bioactive Compounds

2011

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CONTENTS 1. Introduction 5004 2. Synthesis of Six-Membered Cyclic Oxime Ethers 1 and 2 5005 2.1. [4 þ 2]-Cycloaddition Reactions 5005 2.2. Intramolecular Cyclization of γ-Functionalized Oximes 5009 2.3. Intramolecular Cyclization of Functionalized O-Substituted Hydroxylamines 5012 2.4. Synthesis of SCOE from N-O-Containing Heterocyclic Derivatives 5012 2.4.1. Synthesis of SCOE from Other 1,2-Oxazines 5012 2.4.2. Synthesis of SCOE from Isoxazolines and Five-Membered Cyclic Nitronates 5014 2.5. Other Methods 5014 3. Chemical Properties of SCOE 5016 3.1. Reduction of SCOE 5016 3.1.1. Reduction of SCOE to Tetrahydro-2H-1,2oxazines 5018 3.1.2. Reduction of SCOE with 1,2-Oxazine Ring-Opening 5020 3.1.2.1. Reduction of SCOE to 1,4-Amino Alcohols. 5020 3.1.2.2. Reduction of SCOE to Carbonyl Compounds. 5021 3.1.2.3. Reduction of SCOE to γ-Hydroxyoximes. 5022 3.1.3. Reduction Reactions of SCOE with 1,2-Oxazine Ring Contraction 5022 3.1.3.1. Reduction of SCOE to Pyrrolidines. 5022 3.1.3.2. Reduction of SCOE to N-Hydroxypyrrolidines. 5023 3.1.3.3. Reduction of SCOE to Pyrroles. 5024 3.1.3.4. Reduction of SCOE to Aziridines. 5025 3.1.3.5. Reduction of SCOE to Furan Derivatives. 5025 3.2. Addition Reactions to the CdN Double Bond of SCOE 5026 3.3. 1,2-Oxazine Ring-Opening in SCOE 5027 3.4. Deoximation of SCOE 5028 3.5. 1,2-Oxazine Ring Rearrangements in SCOE 5028 3.6. 1,2-Oxazine Ring Fragmentation Reactions in SCOE 5030 4. SCOE in the Synthesis of Natural Products and Biologically Active Compounds 5031 4.1. Synthesis of Amino Acids 5032 4.2. Synthesis of Polyhydroxylated Pyrrolidines 5033 4.3. Synthesis of Pyrrolizidine and Indolizidine Alkaloids and Their Analogs 5033 4.4. Synthesis of Biologically Active 2-Aryl-Substituted Pyrrolidines and Amines 5035 4.5. Synthesis of Other Natural Compounds 5036 5. Conclusion 5037 Author Information 5037 Biographies 5038 Acknowledgment 5038 References 5038

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Section: Chemical Properties Of Scoesupporting

confidence: 60%

Section: Synthesis Of Six-membered Cyclic Oxime Ethers 1 Andmentioning

confidence: 99%

Chemistry of Six-Membered Cyclic Oxime Ethers. Application in the Synthesis of Bioactive Compounds

2011

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“…1,2‐Oxazines are also available by the cyclization of alkenyl‐substituted oximes using NBS,16 diphenyl diselenide,17 acid,18 UV light,19 and iodine 20. Cyclization of γ‐sulfonyloximes,21 γ‐chlorooximes22 and γ,δ‐epoxyoxime23 by using base is also a method for the preparation of 1,2‐oxazines. Other synthetic approaches to 1,2‐oxazines rely on Lewis acid‐catalyzed cyclization of allene‐substituted oxime24 and acid‐catalyzed cyclization of cyclopropyloxime 25.…”

Section: Resultsmentioning

confidence: 99%

Asymmetric Aldol Reaction of α‐Acetoxyimino Aldehydes and its Application in the Synthesis of Substituted 1,2‐Oxazine Derivatives

et al. 2014

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Abstract:We have developed an asymmetric crossaldol reaction of a-acetoxyimino aldehydes with aldehyde pro-nucleophiles, catalyzed by proline, to afford g-acetoxyimino-b-hydroxy aldehydes in good yield with excellent enantioselectivity. The obtained aldol products have been successfully converted to 1,2-oxazines with four contiguous chiral centers in excellent diastereoselectivity in one-pot via sequential reactions such as deacetylation, oxy-Michael reaction and reduction.

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“…Finally, epibromohydrin ( 6 ) has been employed in the synthesis of 6-hydroxymethyl-5,6-dihydro-4 H -1,2-oxazines . In that respect, the reaction of epibromohydrin ( 6 ) with dilithiated oximes 277 , generated from oximes 276 with n -butyllithium, led to the selective formation of 1,2-oxazines 279 in 30–81% yield by initial nucleophilic substitution of epibromohydrin ( 6 ) to form intermediate 278 , which cyclizes to the dihydro-1,2-oxazine derivatives 279 (Scheme ).…”

Section: Applications Of Epichlorohydrin and Epibromohydrin In The Sy...mentioning

confidence: 99%

Epihalohydrins in Organic Synthesis

et al. 2012

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One-Pot Cyclizations of Dilithiated Oximes and Hydrazones with Epibromohydrin. Efficient Synthesis of 6-Hydroxymethyl-5,6-dihydro-4H-1,2-oxazines and Oxazolo[3,4-b]pyridazin-7-ones

Cited by 20 publications

References 34 publications

Chemistry of Six-Membered Cyclic Oxime Ethers. Application in the Synthesis of Bioactive Compounds

Chemistry of Six-Membered Cyclic Oxime Ethers. Application in the Synthesis of Bioactive Compounds

Asymmetric Aldol Reaction of α‐Acetoxyimino Aldehydes and its Application in the Synthesis of Substituted 1,2‐Oxazine Derivatives

Epihalohydrins in Organic Synthesis

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