Dipeptide analogs. Versatile synthesis of the hydroxyethylene isostere

Kempf, Dale J.

doi:10.1021/jo00371a001

Cited by 63 publications

(17 citation statements)

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“…The relative stereochemistry of trans-oxazolidinone 1 was unequivocally established by analysis of the 1 H NMR spectrum. The coupling constant ( 3 J H4-H5 6.4 Hz) indicates that these hydrogens are on opposite faces of the heterocyclic ring [27][28][29][30] (Figure 2). Spectroscopic data of this stereoisomer are totally in agreement with those reported in the literature.…”

Section: Resultsmentioning

confidence: 99%

New Approach for the Stereoselective Synthesis of (+)-epi-Cytoxazone

Miranda¹,

Sartori²,

Diaz³

et al. 2018

J. Braz. Chem. Soc.

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The stereoselective total synthesis of (+)-epi-cytoxazone was performed satisfactorily in 8 steps, in 17% overall yield, via a novel route from 2,3-O-(3-pentylidene)-(R)-glyceraldehyde. The bulky group alkene-ketal allowed intramolecular control of the target molecule's asymmetric centers in the dihydroxylation step by promoting the approach of OsO 4 to the face opposite to that of the ketal group.

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Section: Resultsmentioning

confidence: 99%

New Approach for the Stereoselective Synthesis of (+)-epi-Cytoxazone

Miranda¹,

Sartori²,

Diaz³

et al. 2018

J. Braz. Chem. Soc.

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“…material and thermal cyclization [70] gave very slow conversion. When we used 6  hydrogen chloride in methanol as [ formation of the chlorinated lactone 23 was observed (Scheme 3 and Table 2, entry 9).…”

Section: Resultsmentioning

confidence: 99%

Aminoalkyl-Substituted α-Methylene-γ-butyrolactones from α-Amino Acids Using an Indium-Mediated Barbier Allyl Addition

Steurer

Podlech²

1999

Eur. J. Org. Chem.

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The indium‐mediated reaction of Z‐protected α‐amino aldehydes 1–6 with 2‐(bromomethyl)acrylates 8/9 in aqueous solvents has been investigated. The preference for the formation of syn‐configured homoallyl alcohols 10–16 (diastereoselectivities ranging from 2:1 to 32:1, yields 68–93%) may be explained by a chelate‐controlled reaction. No racemization occurred during the preparation and transformation of the amino aldehydes. Acid‐catalyzed esterification (H2SO4 in Et2O) led to α‐methylene‐γ‐butyrolactones 17–22 with yields ranging from 89 to 97%. The configurations of all diastereoisomers were established by five X‐ray crystallographic analyses and by comparision of the NMR spectra.

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“…The stereocenter at C4 is epimeric to that of target natural product 2, however this stereochemistry was useful in the induction of the desired C6 stereocenter by hydrogenation. 107,108 Reduction of 144 with H 2 , Pd/C in MeOH/AcOH (2 : 1) produced compound 145 in 99% yield. The stereochemistry of reduced product 145 was conrmed by XRD analysis.…”

Section: Total Synthesis Of Neooxazolomycin By Kimmentioning

confidence: 99%