Degradation of Some Phthalideisoquinolines with Ethyl Chloroformate-Stereochemical Aspects.

Lee, Dong‐Ung; Iwasa, Kinuko; Kamigauchi, Miyoko; Takao, Narao; Wiegrebe, Wolfgang

doi:10.1248/cpb.39.1944

Cited by 3 publications

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“…The necessary substituted 2-iminooxetanes (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) (Table I) were synthesized in one simple step from the corresponding ketene imines and commercially available aldehydes. The unsymmetrically substituted ketene imines afforded diastereomeric mixtures of the corresponding (E)and (2)-oxetanes, which were separated in many cases by flash chromatography (4, 5, 7, and 10-16, Table I).…”

Section: Resultsmentioning

confidence: 99%

2-Iminooxetane chemistry. 3. Synthesis of .beta.-hydroxy amides

Barbaro¹,

Battaglia²,

Giorgianni³

1992

J. Org. Chem.

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MS (EI, 15 ev) m / z (relative intensity) 316 (M' , 69.4), 273 (100.0). Tetracyclo[ 1 1.5.2.~JS.0ZJ6]eicosane-15,17,19-trione Tris-(tosylhydrazone) (23). The trione (22,22 mg, 0.07 mmol) and tosylhydrazine (64 mg, 0.35 "01)were dissolved in anhydrous ethanol (3 mL) which contained 2 drops of concentrated HCl. The mixture which reaulted was allowed to heat at reflux. The reaction progress was monitored by TLC (EtOAc/hexane, 32) on silica gel. After 4 h, examination of the reaction mixture by TLC indicated the presence of a new component and the absence of starting material. The reaction mixture was allowed to cool to 25 OC, and the ethanol was removed under reduced pressure. The residue was dissolved in CHzClz (100 mL), washed with water and brine, and dried (MgS04). The solvent was removed in vacuo to provide a crude solid which was chromatographed (EtOAc/ hexane, 2:3) to provide tris(tosy1hydrazone) (40 mg, 70%) 23: FTIR (KBr) 1650 cm-I; 'H NMFt (250 MHz, CDC13) 6 2.42 (3 H, s, CH3), 2.43 (6 H, s, 2 CH3), 1.20-3.50 (28 H, m), 7.20-8.05 (12 H, m).Attempted Preparation of 1,2:16,17-Bisdecanododecahedrane (3) via the Photodimerization of Ellacene (4). Ellacene (4,30 mg, 0.11 "01) was dissolved in pentane (0.1 mL) and transferred into a quartz tube ( 2 " diameter) with a NMFt cap. Argon was carefully bubbled into the solution for 5 min, and then it was placed in a photochemical apparatus (low-pressure Hg lamp with X = 254 nm). The reaction progress was monitored by GC/MS (temperature 200 "C; initial time, 2 min, program rate, 10 OC/min; final temperature 260 OC; final time, 5 min). The GC/MS results suggested no change over a 3-day period [ t~( 4 ) = 7.0 min]. The reaction was worked up, and the NMFt (lH, '%) spectrum of the entire mixture was identical to that of authentic ellacene. The same reaction was repeated with a light source at 214 nm for 24 h; GC/MS of the reaction mixture indicated no change of the starting triene. The starting ellacene was recovered and found to be identical with an authentic sample of ellacene, 4 PH NMR. TLC). Attempted Preparation of 1,2:16,17-Bisdecanododecahedrane (3) via High-pressure Dimerization of 1,lO-Decanotriquinacene (4, Ellacene).High pressure was generated in a gasketed diamond anvil cell, and ellacene was directly introduced via a syringe into the gasket hole, which also contained a ruby chip for pressure calibration. After each high-pregsure experiment, the contents of the cell were removed with ca. 2-4 pL of benzene and analyzed by GC/MS on a Finnigan 8230 m m spectrometer using on-columm injection of the entire sample. The GC/MS results indicated that pressurization of ellacene to nearly 20 GPa (1 GPa = 10 kbar) and/or exposure to 30gnm ultraviolet radiation at 5 GPa failed to produce any detectable products except the starting ellacene. Only starting ellacene was obtained. Under the same conditions triquinacene underwent [2 + 21 dimerization.lW Acknowledgment. We wish to thank the NSF (CHE 9111392) and donors of the Petroleum Research Fund, administered by the American...

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Section: Resultsmentioning

confidence: 99%

2-Iminooxetane chemistry. 3. Synthesis of .beta.-hydroxy amides

Barbaro¹,

Battaglia²,

Giorgianni³

1992

J. Org. Chem.

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“…As recently reported 3 ), the phthalideisoquinoline alkaloid (-)-oc-narcotine (1) reacts with ethyl chloroformate to yield the benzyl chloride 2 at room temp, or the enol lactones 3 and 4 in refluxing CH 2 C1 2 (Scheme 1).…”

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confidence: 78%

Different EI‐MS Fragmentations of the (E)‐ and (Z)‐Enol Lactones Derived from α‐Narcotine

Lee

Mayer

Wiegrebe

et al. 1993

Archiv der Pharmazie

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As recently reported3), the phthalideisoquinoline alkaloid (-)-a-narcotine (1) reacts with ethyl chloroformate to yield the benzyl chloride 2 at room temp. or the enol lactones 3 and 4 in refluxing CH2CI2 (Scheme 1).The EI-MS (70120 eV) of the (E)-and (Z)-isomers 3 and 4 are remarkably different (Fig. 1). While the fragmentation sequences of the M+' of 4 are in perfect accord to those of pertinent stilbenes derived from laudanosine (e.g. formal fragmentation of the stilbene double bond after two [ 1,5-H] shifts of the ethylamine side hai in)^,^), the ionized (E)-isomer 3 shows an additional fragmentation pathway giving rise to fragment ions at mlz 279, 278, 250, and 206 with a re]. intensity (%) of <0.5/<0.5, 60147, 813, and 4/<0.5 (70120 eV), respectively (the intensity of the ion at mlz 279 was calculated by substraction of the 13C isotope satellite).By analysis of metastable ions of 3+' in the first field free region of a double focussing mass spectrometer (BE-and B2/E-linked scans) it was corroborated that the ion at m/z 279 originates exclusively from the molecular ion, and that it is the sole precursor of the characteristic ion at m/z 278 which successively ejects C2H4 (m/z 250) and C 0 2 (m/z 206).Molecular ions of geometrical isomers can retain their ground state geometry during electron impact ionization',*). This explains different intensities of common peaks and also individual fragmentation patterns. Nevertheless, many (E/.Z)-isomers provide virtually identical mass spectra.

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“…Heating the chloro-urethan 9-1 with water or treatment with moist Ag 2 0 in dioxan produced the hydroxy-urethan 10. In the meantime Lee et al 8) have prepared this compound by a different procedure and have established its stereochemistry (aS,9S) by X-ray analysis. Compound 10 is also obtained on prolonged reaction of a-narcotine (5) with ECF/KOH in CHC1 3 /Et 2 0.…”

Section: Ringöffnung Von Phthalidisochinolin-alkaloiden Durch Chlorammentioning

confidence: 99%

Ring‐cleavage of Phthalidisoquinoline Alkaloids by Ethyl Chloroformate

Angerer

Ambros

et al. 1992

Archiv der Pharmazie

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Degradation of (‐)‐α‐narcotine (5), (‐)‐β‐narcotine (6), and (‐)‐β‐hydrastine (7) with ethyl chloroformate (ECF) affords the chloro‐urethans 9 and 18, respectively. Diastereomer 9‐I is easily hydrolyzed to the hydroxy‐urethan 10, whilst 18 is converted to the methoxy‐analogue 19. The stilbene lactone 11 is obtained from 9‐I by treatment with DBU, the analogous stilbene 17 arises already when 7 is reacted with ECF. ‐ Hydroxy‐urethan 10 ‐ a phenylogous aldol ‐ is split by OH− to aldehyde 13 and to meconine (14). LiAlH4‐reduction of 10 yields the stereochemically homogenous triol 15, which is cyclized to diastereomers of the 3‐phenyl‐isochroman 16 under acidic conditions.

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Degradation of Some Phthalideisoquinolines with Ethyl Chloroformate-Stereochemical Aspects.

Cited by 3 publications

References 4 publications

2-Iminooxetane chemistry. 3. Synthesis of .beta.-hydroxy amides

2-Iminooxetane chemistry. 3. Synthesis of .beta.-hydroxy amides

Different EI‐MS Fragmentations of the (E)‐ and (Z)‐Enol Lactones Derived from α‐Narcotine

Ring‐cleavage of Phthalidisoquinoline Alkaloids by Ethyl Chloroformate

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