An Improved Enantiospecific Synthesis of Statine and Statine Analogs via 4-(<i>N,N</i>-Dibenzylamino)-3-keto Esters

Hoffman, Robert V.; Tao, Junhua

doi:10.1021/jo961836g

Cited by 48 publications

(35 citation statements)

References 27 publications

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“…Their synthesis consists of diazotization of the corresponding amino acids with sodium nitrite in a 0.5 M sulfuric acid solution. 9 The procedure is very simple and seems to be general although the yields of a-hydroxy acids were sometimes unsatisfactory. For example, (S)-2-hydroxy-4-methylpentanoic acid 2c and (2S,3S)-2-hydroxy-3-methylpentanoic acid 2d were obtained in 65-73% yields, while the yield of (S)-2-hydroxy-3-methylbutyric acid 2b was only 25%, which is too far below the level acceptable in a multistep synthesis.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of new chiral ionic liquids from α-hydroxycarboxylic acids

Poterała

Plenkiewicz

2011

Tetrahedron: Asymmetry

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Section: Resultsmentioning

confidence: 99%

Synthesis of new chiral ionic liquids from α-hydroxycarboxylic acids

Poterała

Plenkiewicz

2011

Tetrahedron: Asymmetry

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“…The utilization of Pd[0] enabled to use mild and neutral conditions for the removal of allylic group and following decarboxylation. This was a significant improvement over the previous method using t-butyl ester [77]. Treatment of the 3-ketosphinganine with NaHMDS followed by TMSCl gave TMS-enol ether, which was oxidized with Pd(OAc) 2 to unsaturated ketone (20).…”

Section: Synthesis Of Sphingosinementioning

confidence: 96%

Synthesis and Structure-Activity Relationships of Skin Ceramides

Novotný¹,

Hrabálek²,

Vávrová

2010

CMC

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Ceramides are a complex group of lipids that has gained much attention as cell signaling molecules and skin barrier constituents. In the skin, these sphingolipids form a major part of the stratum corneum intercellular lipid matrix, which is the barrier for penetration of most compounds. The development of such a protective layer was a critical step in the evolution of life on a dry land. Moreover, prominent skin diseases such as psoriasis and atopic dermatitis are associated with diminished ceramide levels and may be effectively improved by exogenous ceramides or their analogues. Since ceramides are not obtained from natural sources in pure form, they are of synthetic interest since 1950's. In this review, we describe sphingosine syntheses from 1998 until 2008, and the synthetic approaches to the unique epidermal ceramides, including the 6-hydroxysphingosine-based ones, the alpha- and omega-hydroxy forms and the omega-acyloxy species. Moreover, the structural requirements of ceramides for a competent skin barrier are discussed, including acyl chain length, trans double bond, acyl alpha-hydroxyl, stereochemistry, omega-linoleyloxy species and ceramide conformation.

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“…The Fmoc protecting group allows for a final purification by crystallization to afford diastereomerically pure products [245]. Using this methodology, a variety of statine analogs, with both natural and unnatural configurations, and with branched and unbranched R groups, have been prepared in four steps from activated a-amino esters in excellent overall yields and diastereoselectivity [246].…”

Section: B-hydroxy-g-substituted G-amino Acidsmentioning

confidence: 99%