Elimination reactions on angular hydroxymethyl group of the lupane skeleton

Vystrčil, A.; Křeček, Václav; Budesinsky, M.

doi:10.1135/cccc19742494

Cited by 3 publications

(7 citation statements)

References 1 publication

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“…[α] D 20 −20.5 ( c 0.2, chloroform); lit. 23 [α] D 20 −31 ( c 1.40). ν max (film): 2946, 2869, 1732, 1451, 1370, 1247, 1026, 981, 740 cm –1 .…”

Section: Methodsmentioning

confidence: 99%

“…The mixture was then left to warm to room temperature and stirred overnight. Solvents were evaporated under reduced pressure and the residue was purified by column chromatography (hexane–ethyl acetate, 9:1 to 5:1) to afford 13 (320 mg, 6%), 58 12 (3.06 g, 56%), 11 (902 mg, 18%), and crude 14 (565 mg, 11%) in order of appearance, all as foams.…”

Section: Methodsmentioning

confidence: 99%

“…Short column chromatography of the residue (hexane–ethyl acetate, 9:1 to 5:1, and hexane–ethyl acetate–methanol, 5:3:1) gave crude acid 14 (202 mg) as an amorphous powder. 58 …”

Section: Methodsmentioning

confidence: 99%

“…Column chromatography of the residue (hexane–ethyl acetate, 7:3 to 1:1) gave 17 (76 mg, 75% after two steps) as a glass. 58 [α] D 20 +17.4 ( c , 0.2 chloroform). ν max (film): 3461, 2947, 2870, 1736, 1704, 1449, 1384, 1254, 1172, 1038, 755 cm –1 .…”

Section: Methodsmentioning

confidence: 99%

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Oxidative Functionalization of Trinor-18α-olean-17(22)-ene Derivatives. Annulation of the E-Ring by an Intramolecular Aldol Reaction

et al. 2021

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cis -Dihydroxylation of trinor-18α-olean-17(22)-ene 2 with osmium tetroxide led to diol 9 . Its cleavage with lead tetraacetate gave tetracyclic ketoaldehyde 10 . By comparison, the ozonation of trinor-18α-olean-17(22)-ene 2 in the presence of p -toluenesulfonic acid gave the corresponding ketoacetal 12 . Both products were subjected to an intramolecular aldol reaction under the acidic conditions and yielded unusual triterpenes bearing a bicyclo[4.3.1]decane fragment ( 22 ). Further manipulation of the protective groups afforded compounds useful in triterpene synthesis, especially in the preparation of potentially biologically active saponins based on a tetracyclic terpene core.

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“…[α] D 20 −20.5 ( c 0.2, chloroform); lit. 23 [α] D 20 −31 ( c 1.40). ν max (film): 2946, 2869, 1732, 1451, 1370, 1247, 1026, 981, 740 cm –1 .…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Short column chromatography of the residue (hexane–ethyl acetate, 9:1 to 5:1, and hexane–ethyl acetate–methanol, 5:3:1) gave crude acid 14 (202 mg) as an amorphous powder. 58 …”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Oxidative Functionalization of Trinor-18α-olean-17(22)-ene Derivatives. Annulation of the E-Ring by an Intramolecular Aldol Reaction

et al. 2021

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“…Moreover, we found that the epoxides rearranged during the chromatography because in an attempted separation we isolated also the ketone XXII (prepared in ref. 1 ). The same rearrangement of an analogous epoxide was observed by us previously 2 .…”

mentioning

confidence: 99%

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

Křeček

Hilgard

Budêšínský

et al. 1995

Collect. Czech. Chem. Commun.

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A series of derivatives with various oxygen functionalities in positions 17,22a or 19,20 was prepared from diene I and olefin XVI by addition and oxidation reactions. The structure of the obtained compounds was confirmed by 1 H NMR, 13 C NMR and IR spectroscopy. The kind of intramolecular association of the 17α-hydroxy group was studied in connection with modification of the side chain and substitution in position 22a. Complete assignment of the hydrogen signals and most of the coupling constants was accomplished using a combination of 1D and 2D NMR techniques. The 1 H and 13 C NMR spectra are discussed.

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ChemInform Abstract: TRITERPENES PART 34, ELIMINATION REACTIONS ON ANGULAR HYDROXYMETHYL GROUP OF THE LUPANE SKELETON

Vystrčil¹,

Křeček²,

Budesinsky³

1974

Chemischer Informationsdienst

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Elimination reactions on angular hydroxymethyl group of the lupane skeleton

Cited by 3 publications

References 1 publication

Oxidative Functionalization of Trinor-18α-olean-17(22)-ene Derivatives. Annulation of the E-Ring by an Intramolecular Aldol Reaction

Oxidative Functionalization of Trinor-18α-olean-17(22)-ene Derivatives. Annulation of the E-Ring by an Intramolecular Aldol Reaction

E-Homolupane Derivatives Substituted in Position 17 and 22a. 1H NMR, 13C NMR and IR Spectra

ChemInform Abstract: TRITERPENES PART 34, ELIMINATION REACTIONS ON ANGULAR HYDROXYMETHYL GROUP OF THE LUPANE SKELETON

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