Stereochemical studies 83 saturated heterocycles 76

Bernáth, G.; Stájer, Géza; Szabó, Angela E.; Fölöp, Ferenc; Sohár, Pàl

doi:10.1016/s0040-4020(01)96537-8

Cited by 54 publications

(16 citation statements)

References 15 publications

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“…[12] The amino acid was esterified in the presence of ethanol and thionyl chloride and then acylated with acetic anhydride, benzoyl chloride, or tert-butoxy pyrocarbonate, resulting in N-acylated amino esters 1a-c, respectively.…”

Section: Resultsmentioning

confidence: 99%

Facile Regio‐ and Diastereoselective Syntheses of Hydroxylated2‐Aminocyclohexanecarboxylic Acids

et al. 2005

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Keywords: Amino acids / Heterocycles / Diastereoselectivity / Structure elucidation By means of total regio-and diastereoselective functionalizations of cis-and trans-2-amino-4-cyclohexenecarboxylic acid derivatives 1, 9, 12 and 16, isomers of 2-amino-4-hydroxycyclohexanecarboxylic acid 8 and 11, and 2-amino-5-hydroxycyclohexanecarboxylic acid 15 and 19 were prepared in good yields, via 1,3-oxazine or γ-lactone intermediates. The enantiomers of 8 and 15 were also prepared by the same

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Section: Resultsmentioning

confidence: 99%

Facile Regio‐ and Diastereoselective Syntheses of Hydroxylated2‐Aminocyclohexanecarboxylic Acids

et al. 2005

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“…The starting aminoalcohols lA, 2A, and 9A were prepared as described earlier [12,13]. AminoaLcohols 5A, 6A, and lOA were prepared as described for cyclohexane derivatives [14]; starting from ethyl cis-and trons-Z-amin0-4-cyclohexene-1carboxylate [12]. The thin layer chromatography pure oily products were used without further purification.…”

Section: Synthesis (Scheme I)mentioning

confidence: 99%

“…Th e 7D-eV mass spec tr a of compou nds 2, 6 and 10.Compound 1 229(8) 228(M+ •, 50),2-77(36). 175(12), 174(100), 173(5), 147(6), 132(33), 120(14), 119 (96), 94( 5), 93(14 ), 92(11), 91(11), 82(38), 79(7),77(29), 67(5) , 65(10). 54( 8), 51(8), 41(8), 39(9 ).…”

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confidence: 99%

Effects of N-substitution on the fragmentations of some cyclohexene-fused 2-N-phenyliminoperhydro-3,1-oxazines and related thiazines

Vainiotalo

Partanen

Fülöp

et al. 1991

J. Am. Soc. Mass Spectrom.

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Six cyclohexene-fused 2-N-phenyliminoperhydro-3,1-oxazines and four related thiazines were prepared and their mass spectrometric behavior was studied by means of metastable ion analysis and exact mass measurement. In most of the fragmentations, extensive rearrangements took place. The decompositions through the retro-Diels-Alder reaction initiated by the double bond dominated in the case of the unsubstituted compounds. The effect of the double bond, however, was greatly outweighed by the effect of the substituent on the ring nitrogen atom. In comparison with the unsubstituted compounds, both electron-releasing (methyl) and electron-withdrawing (benzyl) substituents increased the contribution of the ring cleavage reactions in the heterocyclic part of the molecule; in the case of the benzyl group the loss of the substituent also became important. For isomeric compounds, the relative peak intensities were so different that such compounds were easy to differentiate.

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“…Sets A-E were reacted in the Ugi reaction as follows. One set of aldehydes, 3 isocyanides (cyclohexyl (a), tert-butyl (b), and benzyl isocyanide (c)) and 3 cyclic β-amino acids (cis-2-aminocyclohexane-(I) [14], cis-2-aminocyclopentane-(III) [15], and cis-2-aminocyclohex-4-enecarboxylic acid (II) [16]) were added to a vessel in equimolar amounts and the mixture was stirred in MeOH at room temperature for 3 days. The solution-phase libraries were purified by column Scheme 1 Formation of azetidinone ring 1 from cyclic β-amino acids (I-III), which supply the carboxylic and amino functions in the Ugi 4-center 3-component reaction (U-4C-3CR).…”

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confidence: 99%