High‐Yield Synthesis of 20‐, 24‐, and 28‐Membered Macropentolide, ‐hexolide, and ‐heptolide, Respectively, from (R)‐ or (S)‐3‐hydroxybutanoic acid under Yamaguchi's macrolactonization conditions

Seebàch, Dieter; Brändli, Urs; Schnurrenberger, P.; Przybylski, Michael

doi:10.1002/hlca.19880710119

Cited by 43 publications

(9 citation statements)

References 36 publications

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“…Finally, as described in Scheme 3, ester 16 was generated from 11 in three steps that included Yamaguchi esterification between acid 12 [27] and alcohol 11 ,hydrogenation of ester 13 to remove a benzyl (Bn) group, and another esterification between alcohol 14 and n-butyryl chloride or sD-acid 15 . The enzymatic precursor 17 was obtained after acid hydrolysis in acetonitrile for 2.5 hrs.…”

Section: Resultsmentioning

confidence: 99%

“…Finally, as shown in Scheme 3, esters 16 were each generated from 11 in three steps that included Yamaguchi esterification between acid 12 [27] and alcohol 11, hydrogenation of ester 13 to remove a benzyl (Bn) group, and further esterification between alcohol 14 and either n-butanoyl chloride or sD acid 15. The enzymatic precursors 17 were obtained after acid hydrolysis in acetonitrile for 2.5 h. It has to be pointed out that workup for most pantetheine derivatives is tedious and usually involves ion-exchange chromatography to neutralize the acid, followed by lyophilization to remove water.…”

Section: Chemoenzymatic Synthesis Of Carbadethia Analogues 26mentioning

confidence: 99%

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Inhibitors of Polyhydroxyalkanoate (PHA) Synthases: Synthesis, Molecular Docking, and Implications

et al. 2014

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Polyhydroxyalkanoate (PHA) synthases (PhaCs) catalyze the formation of biodegradable PHAs that are considered as an ideal alternative to nonbiodegradable synthetic plastics. However, study of PhaC has been challenging because the rate of PHA chain elongation is much faster than that of initiation. This difficulty along with lack of a structure has become the main hurdle to understand and engineer PhaCs for economical PHA production. Here we reported the synthesis of two carbadethia CoA analogs, sT-CH2-CoA 26a and sTet-CH2-CoA 26b as well as sT-aldehyde 29 as new PhaC inhibitors. Study of these analogs with PhaECAv revealed that 26a/b and 29 are competitive and mixed inhibitors, respectively. It was observed that CoA moiety and PHA chain extension can increase binding affinity, which is consistent with the docking study. Estimation from Kic of 26a/b predicts that a CoA analog attached with an octameric-HB chain may facilitate the formation of a kinetically well-behaved synthase.

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Section: Resultsmentioning

confidence: 99%

Section: Chemoenzymatic Synthesis Of Carbadethia Analogues 26mentioning

confidence: 99%

Inhibitors of Polyhydroxyalkanoate (PHA) Synthases: Synthesis, Molecular Docking, and Implications

et al. 2014

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“…plates; detection either with U V or by dipping into a s o h of I, (30 g) and KI (2 g) in EtOH/H,O 1 : 1 (400 ml) and drying in the air. 2980w, 1450m, 1420rn, 1360s, 1305~3, 1280s, 1210vs, 11703, S-Methyl-l,2-dithiolane-3-thione (9). An analogous run with 1 (10.0 g, 39 mmol) and 5 (50.0 g, 120 mmol) in o-xylene (100 ml) and a reaction time of 17 h gave, after FC (pentane+pentane/Et20 l:l), 8 (1.19 g, 16%), 7 (2.42 g, 21%), and 8/9 which could be separated by an additional FC (CH,Cl,/pentane 1:20 (500 ml), then Et,O/pentane 1:l): 8 (236 mg, 2%) and 9 (230 mg, 1.3%; orange, clear oil).…”

Section: )mentioning

confidence: 99%

Preparation, Structure, and Reactivity of Thioxo and Imino Derivatives of the Triolide (and Pentolide) from (R)‐3‐Hydroxybutanoic Acid

Brunner

Kühnle²,

Seebàch³

1996

Helvetica Chimica Acta

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Reaction of the triolide 1 from (R)-3-hydroxybutanoic acid with Lawesson's reagent 5 leads to the mono-, di-, and trithio derivatives 6-8 which can be isolated in pure form (2040% yields), and which have crystal structures very similar to the parent triolide 1 (Fig.1). Similarly, pentolide 3 is converted to mixtures of various thio derivatives, three of which are separated (1612) by HPLC and fully characterized. The X-ray structures of the mono-and of one of the dithiopentolides (10, 12) differ remarkably from each other (Fig.3). Reduction of the thiotriolides 6-8 (NaBH,, R,SnH, Cl,SiH, Raney -Ni) gives 12-membered rings containing up to three ether groups (chiral crown ethers, 15, 17-19) in poor yields. The thiotriolides react spontaneously and in yields of up to 96% with ammonia, certain primary amines, and hydroxylamine to give imine and oxime derivatives with intact 12-membered-ring backbones (20, 22-24, 30, see crystal structures in Figs. 4-7). The rigid structure of all the derivatives of triolide 1 puts the C=O, C=S, and C=NR 0-, S-, and N-atoms in juxtaposition (a feature reminiscent of the side chains in the iron-binder enterobactin, Fig. 6). Imines containing PPh, groups are prepared (30,33,35) from the thiotriolides and tested as chiral ligands for PdT'-catalyzed 1,3-diphenylallylations (-37, enantiomer ratio up to 77:23). The reactions described demonstrate that multiple reactions of the triolide 1 from (R)-3-hydroxybutanoic acid which proceed through tetrahedral intermediates are possible without ring opening -the skeleton is remarkably stable, and this might be exploited as a template for bringing up to three pendent substituents into close proximity to allow a study of their interactions and cooperative properties. Also, the di-and trithio derivatives 7 and 8 could be used for cross-linking in molecules containing primary NH2 groups.

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“…Qualitatively, the NMR spectra of cyclic and linear OHBs [10] look very similar, exhibiting only one set of average signals for all the residues. Thus, the cyclic hexamer, a 24-membered ring, that exists in crystals in a folded and twisted conformation resembling the number 8 ( Fig.…”

mentioning

confidence: 94%

On the Solution Structure of PHB: Preparation and NMR Analysis of Isotopically Labeled Oligo[(R)-3-hydroxybutanoic Acids] (OHBs)

Waser¹,

Rueping²,

Seebàch³

et al. 2001

HCA

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Dedicated to Professor Edgar Heilbronner with best wishes on the occasion of his 80th birthdayWhile the chain conformation of poly-and oligo[(R)-3-hydroxybutanoate] (PHB, OHB) is known to be 2 1 -and 3 1 -helical in stretched fibers and in the crystalline state, respectively (Fig. 2), the structure in solution is unknown. To be able to determine the NMR-solution structure, specifically labeled linear oligomers have been prepared: a 16-mer consisting of alternating pairs of fully 13 C-labeled and non-labeled residues (1) and a 20-mer containing an O-13 CH( 13 CH 2 D)-13 CHD Si -13 CO residue in position 9 (from the O-terminus) and a fully 13 Clabeled residue in position 12 (2), both with (t-Bu)Ph 2 Si protection at the O-and Bn protection at the Cterminus. The labeled (R)-3-hydroxybutanoic acid building blocks were prepared by Noyori hydrogenation of the ethyl ester of fully 13 C-labeled acetoacetic acid, and the D-atoms were incorporated by D 2 /Pd-C reduction of a previously reported dibromo-1,3-dioxinone 8 (Scheme 1). The oligomers were obtained by a series of fragment couplings (Schemes 2 and 3). 600-MHz NMR COSY, HSQC, ROESY, and cross-correlated relaxation measurements (Figs. 4 ± 6, 9, and 12, and Tables 1 ± 3) at different temperatures and interpretations thereof led to assignments of all resonances, including those from the diastereotopic C(2)H 2 protons, and to determination of the conformationally averaged dihedral angles f 2 and f 3 (Figs. 2, 7, and 8) in the chain of the oligoester. The conclusions are: all but five or six terminal residues adopt the same conformation; the 2 1 helix is not the predominant secondary structure; the structure of the HB chain is averaged, even at ±308. Our investigation confirms the high flexibility of the polyester chain, a property that has been deduced previously from biological studies of PHB in membranes, in ion channels, and as appendage of proteins.

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High‐Yield Synthesis of 20‐, 24‐, and 28‐Membered Macropentolide, ‐hexolide, and ‐heptolide, Respectively, from (R)‐ or (S)‐3‐hydroxybutanoic acid under Yamaguchi's macrolactonization conditions

Cited by 43 publications

References 36 publications

Inhibitors of Polyhydroxyalkanoate (PHA) Synthases: Synthesis, Molecular Docking, and Implications

Inhibitors of Polyhydroxyalkanoate (PHA) Synthases: Synthesis, Molecular Docking, and Implications

Preparation, Structure, and Reactivity of Thioxo and Imino Derivatives of the Triolide (and Pentolide) from (R)‐3‐Hydroxybutanoic Acid

On the Solution Structure of PHB: Preparation and NMR Analysis of Isotopically Labeled Oligo[(R)-3-hydroxybutanoic Acids] (OHBs)

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