Diastereoselective Formation of (<i>Z</i>)-Didehydroamino Acid Esters

Schmidt, Ulrich; Grießer, Helmut; Leitenberger, Volker; Lieberknecht, Albrecht; Mangold, Rainer; Meyer, Regina; Riedl, Bernd

doi:10.1055/s-1992-26143

Cited by 143 publications

(83 citation statements)

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“…The desired dehydroamino acids were prepared by olefination of 46 with the phosphonate derived from Z-or Boc-protected methyl glycinate [50]. This provided mixtures of the diaster- …”

mentioning

confidence: 99%

Synthesis of Glycaro‐1,5‐lactams and Tetrahydrotetrazolopyridine‐5‐carboxylates: Inhibitors of β‐D‐Glucuronidase and α‐L‐Iduronidase

Pabba

Rempel

Withers

et al. 2006

Helvetica Chimica Acta

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The known glucaro-1,5-lactam 8, its diastereoisomers 9 -11, and the tetrahydrotetrazolopyridine-5-carboxylates 12 -14 were synthesised as potential inhibitors of b-D-glucuronidases and a-L-iduronidases. The known 2,3-di-O-benzyl-4,6-O-benzylidene-D-galactose (16) was transformed into the D-galactaroand L-altraro-1,5-lactams 9 and 11 via the galactono-1,5-lactam 21 in twelve steps and in an overall yield of 13 and 2%, respectively. A divergent strategy, starting from the known tartaric anhydride 41, led to the D-glucaro-1,5-lactam 8, D-galactaro-1,5-lactam 9, L-idaro-1,5-lactam 10, and L-altraro-1,5-lactam 11 in ten steps and in an overall yield of 4 -20%. The anhydride 41 was transformed into the L-thre-A C H T U N G T R E N N U N G uronate 46. Olefination of 46 to the (E)-or (Z)-alkene 47 or 48 followed by reagent-or substrate-controlled dihydroxylation, lactonisation, azidation, reduction, and deprotection led to the lactams 8 -11. The tetrazoles 12 -14 were prepared in an overall yield of 61 -81% from the lactams 54, 28, and 67, respectively, by treatment with Tf 2 A C H T U N G T R E N N U N G O and NaN 3 , followed by saponification, esterification, and hydrogen-A C H T U N G T R E N N U N G olysis. The lactams 8 -11 and 40 and the tetrazoles 12 -14 are medium-to-strong inhibitors of b-D-glucuronidase from bovine liver. Only the L-ido-configured lactam 10 (K i = 94 mM) and the tetrazole 14Introduction. -b-D-Glucuronidases (EC 3.2.1.31, family 2) 1 ) and a-L-iduronidases (EC 3.2.1.76, family 39) remove glycuronic acid residues from the non-reducing end of glycosaminoglycans such as chondroitin sulfate and hyaluronic acid.

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“…The desired dehydroamino acids were prepared by olefination of 46 with the phosphonate derived from Z-or Boc-protected methyl glycinate [50]. This provided mixtures of the diaster- …”

mentioning

confidence: 99%

Synthesis of Glycaro‐1,5‐lactams and Tetrahydrotetrazolopyridine‐5‐carboxylates: Inhibitors of β‐D‐Glucuronidase and α‐L‐Iduronidase

Pabba

Rempel

Withers

et al. 2006

Helvetica Chimica Acta

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“…8 Further treatment of 1 with excess hydrazine hydrate in methanol at r.t. gave the pyrazolidinone 2 in 85% yield. Acid-catalyzed treatment of 2 with benzaldehyde and 2,6-dichlorobenzaldehyde gave the corresponding azomethine imines 3a and 3b in 81% and 73% yield, respectively (Scheme 1).…”

Section: Resultsmentioning

confidence: 99%

“…Quite surprisingly and in contrast to their close N-benzoylated analogues, [5][6][7][8][9][10] (4R*,5R*)-4-benzyloxycarbonylamino-5-phenylpyrazolidin-3-one 2 and its azomethine imine derivatives 3 undergo 'ring switching' transformations into 3-aminoimidazolidine-2,4-diones 4 and 8, respectively. To the best of our knowledge, these are the first examples of such ring transformation (i.e.…”

Section: Discussionmentioning

confidence: 99%

Serendipity at work: unexpected ring transformations of 4 aminopyrazolidin-3-ones into N-aminohydantoins

Novak¹,

Bezenšek²,

Grošelj³

et al. 2010

Arkivoc

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Catalytic hydrogenation of (4R*,5R*)-4-benzyloxycarbonylamino-5-phenylpyrazolidin-3-one 2 in the presence of Pd-C furnished an unexpected 'ring switching' transformation product, 3-amino-5-benzylimidazolidine-2,4-dione 4. Furthermore, heating of azomethine imines 3a,b (derived from 2 and aromatic aldehydes) afforded the corresponding (Z)-5-benzylidene-3-[(E)-benzylideneamino]imidazolidine-2,4-diones 8a,b as ring transformation products. Both reactions are explainable by cleavage of the C(5)-N(1) single bond in substrates 2 and 3 followed by cyclocondensation of the amide nitrogen to the carbamate carbonyl group. The structure of hydantoin 8a was confirmed by X-ray diffraction.

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“…Therefore, we examined amide bond formation with a fully unprotected compound (Scheme 4). Removal of the tert-butoxycarbonyl moiety provided the diamine intermediate (19). Amide bond formation proceeded smoothly to yield the primary amide 20.…”

Section: Resultsmentioning

confidence: 99%

“…The compound is also interesting from a synthetic chemistry standpoint, because it possesses distinctive structural characteristics. Roquefortine C contains the unusual E-dehydrohistidine moiety, a system that typically undergoes facile isomerization under acidic, basic, or photochemical conditions (17)(18)(19)(20)(21). This functional group is found in only two natural products, the other being oxaline (22).…”

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confidence: 99%

Synthetic studies of roquefortine C: Synthesis of isoroquefortine C and a heterocycle

Richard

Schiavi

Joullié

2004

Proc. Natl. Acad. Sci. U.S.A.

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Diastereoselective Formation of (Z)-Didehydroamino Acid Esters

Cited by 143 publications

References 0 publications

Synthesis of Glycaro‐1,5‐lactams and Tetrahydrotetrazolopyridine‐5‐carboxylates: Inhibitors of β‐D‐Glucuronidase and α‐L‐Iduronidase

Synthesis of Glycaro‐1,5‐lactams and Tetrahydrotetrazolopyridine‐5‐carboxylates: Inhibitors of β‐D‐Glucuronidase and α‐L‐Iduronidase

Serendipity at work: unexpected ring transformations of 4 aminopyrazolidin-3-ones into N-aminohydantoins

Synthetic studies of roquefortine C: Synthesis of isoroquefortine C and a heterocycle

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