Practical synthesis of (R)-γ-amino-β-hydroxybutanoic acid (GABOB) from (R)-epichlorohydrin

(R)-Epichlorohydrin has efficiently been converted to the hypotensive and antiepileptic compound, (R)-γ-amino-β-hydroxybutanoic acid (GABOB), in six steps in 57% overall yield.     

Total Synthesis of (-)-Baimuxifuranic Acid

ThenatieChenmanginclha,oneofthemoStbeandexpensivCherbaldrugSin~tionalChjnsemdednesisthewoodypartofAquIIarasinensisW.)Gilg.,whoseVofatileoilseforitaIUUnberofinterestinbiologicalandphannacologicalactivities,suchasanestheha,muscularrelaxationandanalgesta'.ReCentiyYanetaI2isolated(-)taim~cacid(1)frOmtheVOboleoilofChenAlang,anddeennineditSStIUCtUrbySpeCtrscoPicmethodandred~1toaknowncornPOunisobaimndnolCoInPOun1isthefirStcarboxylicacidwithdihydragarohanskeletonisolatedfromnisources.He…     

Synthesis of β-amino acid derivatives via copper-catalyzed asymmetric 1,4-reduction of β-(acylamino)acrylates

A new set of reaction conditions has been established to facilitate the copper-catalyzed enantioselective 1,4-reduction of β-(acylamino)acrylates toward a selection of β-alkyl-β-amino acid derivatives in high yields and with uniformly high ee values (up to 99%) irrespective of the use of (E)- or (Z)-substrates.     

Synthesis of α-hydroxy(polyprenyl) bisphosphonates

Bisphosphonates derived from natural terpenes were synthesized by phosphonylation of corresponding aldehydes. The general strategy of introduction of the phosphonate groups into the polyprenol molecule involves successive treatment of a hydroxyl compound by Swern reagent to oxidize the C-OH group into C=O and a (EtO)₃P/[PyH]⁺ClO _? ⁴ mixture to phosphylate the resulting carbonyl compound.     

Synthesis and microbial transformation of β-amino nitriles

Rhodococcus equi A4, Rhodococcus erythropolis NCIMB 11540 and Rhodococcus sp. R312 were investigated towards their ability to produce β-amino amides and acids from β-amino nitriles. The microorganisms show comparable trends: five-membered alicyclic 2-amino nitriles were transformed significantly faster than the six-membered compounds and the products of trans-2-amino nitriles (amides and acids) were formed considerably faster than the cis-counterparts (amides). The trans-five membered nitriles gave the amides (1b, 5b) in excellent enantiomeric excess (94-99%), the biotransformation of trans-six membered substrates resulted in the formation of the acid (3c, 7c) in excellent ee (87-99%). The ee's of the cis-compounds were throughout lower. Fifteen new substances were synthesized and characterized in the course of this work.     

A Convenient Synthesis of β-Amino Acid

We have reported the reductive cleavage of azlactones¹ and phenylhydrazones² of carbonyl compounds in the presence of a suitable catalyst. In this paper a general method involving a one step synthesis of β-amino acid^3,4, in good yield, through catalytic reduction of oximes of α-β-unsaturated acid is reported. This method involves the reaction of α, β-unsaturated acid with hydroxylamine hydrochloride in the presence of sodium acetate. Markovnikov's rule is followed in the synthesis of oximes of α, β-unsaturated acids.     

Zearalenone Mimics: Synthesis of (E)-6-(1-Alkenyl)-substituted β-Resorcylic Acid Esters

Two versatile strategies for the synthesis of mimics of the Fusarium mycotoxin zearalenone (1) have been developed. Optimized preparation of (E)-6-(1-alkenyl) substituted β-resorcylic acid esters was realized via ortho-directed lithiation of variable substrates combined with allylation/isomerization or via formylation/Schlosser–Wittig olefination using different protective group patterns. Spontaneous decarboxylation of (E)-6-(1-alkenyl) substituted β-resorcylic acids indicated the influence of this substituent on the chemical behavior of these compounds. These mimics were already used for the development of optimized standard protocols for the synthesis of phase II metabolites of ZEN (glucosides, glucuronides), and further applications (i.e., sulfate conjugates) are still under investigation.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Synthesis of (4R)-α-Terpineol

Thesynthesisofopticallyactivecompoundsisanimportantissueinmodemorgan-icchendstry-7-Terpineol,anaturalproductisolatedfrompetitgrainoil,longleafpineoi1andcaeputoill'J,hasbeenasynthetictargetduringthecourseofourstudiesontheasymmetriccatalisedDiels-AlderreactionlvInthispaper,l-phenylsulfOnyl-3-buten-2-one(l)wasusedasthesulfOnyl-functionalizedche1atingenoneforthesynthesischiral2-Terpineol(5)byaasymmetriccata1isedDiels-Alderreaction.TherouteforthesynthesisofopticallyaCtivea-Terpineo1(5)isshownin…     

Dehydration of β-Hydroxy-α-amino Acid Derivatives With Phenyltriflimide

Conversion of N-protected β-hydroxy-α-amino esters to corresponding didehydroamino esters has been achieved using phenyltriflimide/triethylamine as a mild dehydrating agent. The selective formation of didehydroalanine derivatives from dipeptides containing, beside a serine residue, another β-hydroxy-α-amino acid, is also described.     

Synthesis of β-amino ketones derived from aminobenzoic acids

Russian Journal of General Chemistry - Alkylation of aminobenzoic acids and their derivatives with 3-diethylamino-1-arylpropan-1-one hydrochlorides gave the corresponding β-aminopropiophenones...     

A Novel Synthesis of β-Hydroxy-α-amino Acids

β-hydroxy-α-amino acids constitute an important class of compounds as naturally occurring amino acids and as components of many complex natural products possessing a wide range of biological activities. [1] As a consequence of the essential role played by these amino acids in the biological systems and their utility as synthetic building blocks, a number of useful strategies have been devised for their preparation. [2]     

Chiral Synthesis of (S)-(+)-γ-Hydroxymethyl-γ-Butyrolactone

S-(+)-γ-hydroxymethyl-gM-butyrolactone has been synthesized from D-ribonolactone as chiral template.     

Synthesis and characterization of novel β-amino acid derivatives

In the work discussed in this paper, novel β-amino acid derivatives were prepared by Michael addition between 3-substituted-2-propenic acid and hydrazine hydrate. The optimum reaction conditions were determined by analyzing the effects of the ratio of the starting materials, temperature, and reaction time. The conclusions were: reaction temperature 80 °C, reaction time 8 h, n (3-substituted-2-propenic acid)/n (hydrazine hydrate) = 1:15. Products were characterized by measurement of melting point, elemental analysis, and IR and ¹H NMR spectroscopy.     

Cyclization of α- and β-amino ketones. (Review)

In this review data on the synthesis of three-, four-, five-, and six-membered heterocycles, as well as of condensed heterocyclic compounds from -amino ketones and Mannich bases are classified for the first time.Samara State Technical University, Samara 433100, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 723–735, June, 1999.     

Synthesis of Cyclic Poly(Methacrylic Acid) by Template Polymerization of β-Cyclodextrin Monomer

Atom transfer radical polymerization of template monomer synthesized by introduction of methacryloyl groups into secondary hydroxyl groups of -cyclodextrin [-CD] was carried out with 1,3-dibromobutane as an initiator. Then, closing of polymerized methacryloyl groups was carried out by reaction of bromine groups at both ends with 1,3-diamino propane [DAP] or 1,4-diamino butane [DAB]. The macrocyclic poly(methacrylic acid) [PMAA] obtained by hydrolysis of products was analyzed by GPC, MALDI-TOF-mass. It was found that template monomer of -CD was effective for synthesisof macrocyclic oligomers and that DAP was the preferred closing reagent for the methacryloyl groups polymerized in the template monomer.     

Total Synthesis of (R)-(−)-β-Cuparenone

Abstract

(R)-(?)-β-Cuparenone has been synthesized from (S)-(+)-acid-2 obtained via resolution of the racemic acid. Two of the noteworthy steps are (a) repeated methylation of ester (+)-8 with LDA/MeI to furnish (+)-10 and (b) the reaction of 12, having two neopentyl units with NaCN.     

Synthesis and Characterization of Novel Biodegradable Polyamides Containing α-amino Acid

The polyamides were obtained from 1,6-hexanediamine and diacylchloride which incorporated α -amino acid residues through interfacial polycondensation. High molecular weight (η_inh = 1.05–1.18 dL/g) polymers were produced with high yields. The structure of polyamides was verified by FT-IR and ¹H NMR spectra. They showed a remarkable ability to develop high crystallinity with melting temperatures in the range 117–191°C and was stable up to 350°C under nitrogen. Two methods such as alkali hydrolysis (10% NaOH w/v, 80°C) and enzymatic hydrolysis were employed for assessing the susceptibility of these polyamides to degradation. A preliminary investigation of the 5-fluorouracil (5-FU) release characteristics of these polyamides showed that the release rate increased with increasing water absorption of the polymers.