Stereocontrolled synthesis of highly oxygenated acyclic systems via the enolate Claisen rearrangement of O-protected allylic glycolates

Gould, Thomas J.; Balestra, Michael; Wittman, Mark D.; Gary, Jill A.; Rossano, Lucius T.; Kallmerten, James

doi:10.1021/jo00226a032

Cited by 69 publications

(29 citation statements)

References 2 publications

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“…The stereotransfer of the allyl group was extremely efficient. We were unable to detect any (Z)-alkene at all [38]. It remains to be established whether the (Z)-crotyl analogue of 12 will behave similarly and what the stereochemical outcome in these systems would be.…”

Section: Methodsmentioning

confidence: 74%

“…85 (2002) 4174 (Z)-configured silyl ketene acetal and, finally, to the syn-isomer 13 as the major product (Scheme 5) [38]. The low stereoselectivity observed with the Cbz-and Bzprotected compounds 11mc and 11mz may have its origin in the presence of the aromatic ring in the protecting groups, which may simply adopt a conformation that prevents chelation.…”

Section: Methodsmentioning

confidence: 99%

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Allylsilane‐Modified Amino Acids from the Claisen Rearrangement

Mohamed

Brook

2002

Helvetica Chimica Acta

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It is an honour to dedicate this paper to Dieter Seebach on the occasion of his 65th birthday. He has been an exceptionally important presence in my professional life, both through his example of how to be a successful scientist and by the many doors he has opened for me. I am very grateful to have had the opportunity to be one of −die Mitarbeiter×.The Claisen rearrangement of the N-protected, silylated allyl glycinates 11 and 12 led to the formation of allyl/silyl-functionalized amino acids 13 and 14 in yields up to 80%. The diastereoisomer ratio varied from 2 : 1 to 29 : 1 for 11mb, and from 2 : 1 to 46 : 1 (syn/anti) for 12mb, depending on reaction conditions, as shown by X-ray crystallographic analysis of 14mb. The relationship between the size of the alkyl groups on the chlorosilane reagent (Me 2 R''SiCl, R'' Cl, Me, t-Bu, Ph) used as an enolate trap and the observed stereoselectivity was investigated in the case of the Ireland ± Claisen variant. Me 3 SiCl gave the best results. However, the size of the alkyl groups on the silylated ester (Me 2 R''Si, R Me, t-Bu, Ph, i-Pr) did not exert a significant effect on the diastereoselectivity or yield of the rearrangement.

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Section: Methodsmentioning

confidence: 74%

Section: Methodsmentioning

confidence: 99%

Allylsilane‐Modified Amino Acids from the Claisen Rearrangement

Mohamed

Brook

2002

Helvetica Chimica Acta

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“…[33] However, these latter conditions have been routinely used in glycolate-Ireland-Claisen rearrangements with no adverse effect on the diastereoselectivity. [13,34] By starting from a purified glycolate 22 and reducing the amount of base and TMSCl (2 equiv each) the diastereomeric ratio was not altered. Switching to LiHMDS as the base also led to a comparable selectivity (24/24' 60:40).…”

Section: Resultsmentioning

confidence: 99%

“…As a-allyloxy esters (Z = OR'') display a lower reactivity than a-allyloxy amides (Z = NR'' 2 ) in [2,3]-Wittig rearrangements, [13,39] a-allyloxy acetamides derived from primary 3-(N-tosylamino)allylic alcohols were selected as substrates and the 1,2-diastereoselectivity of such reactions was first addressed.…”

Section: A C H T U N G T R E N N U N G [23]-sigmatropicmentioning

confidence: 99%

Synthesis of 1,2‐Amino Alcohols by Sigmatropic Rearrangements of 3‐(N‐Tosylamino)allylic Alcohol Derivatives

Barbazanges

Meyer

Cossy

et al. 2011

Chemistry A European J

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Sigmatropic rearrangements of 3-(N-tosylamino)allylic alcohol derivatives, a particular subclass of functionalized enamides, have been investigated. Whereas the presence of the nitrogen atom alters the stereochemical outcome of Ireland-Claisen rearrangements of glycolates derived from such substrates, [2,3]-Wittig rearrangements of α-allyloxy acetamides or propargylic ethers derivatives provide access to a wide variety of functionalized 1,2-amino alcohols usually with high levels of stereocontrol, as well as to heterocyclic compounds. The stereoselectivity issues of these rearrangements (1,2-diastereoselectivity, auxiliary-induced diastereoselection, chirality transfer, and double stereodifferentiation) were thoroughly investigated.

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“…31 The Irvine-Purdie method has been used to achieve i) mono-alkylations; 32–36 ii) bisalkylation of unhindered diols such as cycohexanediol; 37 and iii) per-methylation of carbohydrates such as glucose, galactose and fructose. 31, 38 Inefficient reaction conditions (e.g.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of norbornane bisether antibiotics via silver-mediated alkylation

et al. 2015

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A small series of norbornane bisether diguanidines have been synthesized and evaluated as antibacterial agents. The key transformation—bisalkylation of norbornane diol 6—was not successful using Williamson methodology but has been accomplished using Ag2O mediated alkylation. Further functionalization to incorporate two guanidinium groups gave rise to a series of structurally rigid cationic amphiphiles; several of which (16d, 16g and 16h) exhibited antibiotic activity. For example, compound 16d was active against a broad range of bacteria including Pseudomonas aeruginosa (MIC = 8 µg/mL), Escherichia coli (MIC = 8 µg/mL) and methicillin-resistant Staphylococcus aureus (MIC = 8 µg/mL).

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Stereocontrolled synthesis of highly oxygenated acyclic systems via the enolate Claisen rearrangement of O-protected allylic glycolates

Cited by 69 publications

References 2 publications

Allylsilane‐Modified Amino Acids from the Claisen Rearrangement

Allylsilane‐Modified Amino Acids from the Claisen Rearrangement

Synthesis of 1,2‐Amino Alcohols by Sigmatropic Rearrangements of 3‐(N‐Tosylamino)allylic Alcohol Derivatives

Synthesis of norbornane bisether antibiotics via silver-mediated alkylation

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