Über die Konstitution des sogenannten Norlupinans B

Prelog, V.; Seiwerth, Rativoj

doi:10.1002/cber.19390720831

Cited by 23 publications

(4 citation statements)

References 3 publications

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“…We envisioned that the corresponding precursor to 4 would be generated from cyclic ketone 5 by a Clemmensen reductive rearrangement. The anomalous Clemmensen reduction of cyclic α-amino ketone was first noticed by Clemo in 1931, clarified by Prelog, and later studied systematically by Leonard and co-workers …”

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confidence: 82%

A Novel and Efficient Total Synthesis of Cephalotaxine

Wang

2003

Org. Lett.

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[reaction: see text] Total synthesis of cephalotaxine (CET), the parent member of a class of structurally unique antileukemia Cephalotaxus alkaloids, was accomplished on the basis of a conceptually novel strategy featuring transannular reductive skeletal rearrangements as the key transformations for the construction of the pentacyclic ring skeleton of CET. The synthetic potential of the designated Clemmensen-Clemo-Prelog-Leonard reductive rearrangement was demonstrated for the first time in a facile synthesis of the benzazepine subunit of CET. A novel endocyclic enamine (cyclopentenone) annulation was discovered and rationalized as an unusual azo-Nazarov-type cyclization.

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confidence: 82%

A Novel and Efficient Total Synthesis of Cephalotaxine

Wang

2003

Org. Lett.

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“…Cierno and Ramag'e (29) report the isolation of two forms of octahydropyrrocoline, as picrates, on Clemmensen reduction of VI. Contrary to the balance of published opinion that the three nitrogen valencies in ring systems are coplanar, Cierno et al (30) considered the two forms of the closely related octahydropyridocoline to be cis-tran$ isomers of the decalin type, owing to the non-planarity of the tervalent nitrogen, but Prelog and Seiwerth (78) have recently shown one of the two forms to be identical with bicyclo[0.3.5]aza-l-decane. The derivation of the two forms of octahydropyrrocoline therefore is thus still obscure.…”

Section: Cooc2h5mentioning

confidence: 98%

The Chemistry of the Pyrrocolines and the Octahydropyrrocolines.

Borrows¹,

Holland²

1948

Chem. Rev.

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“…This was the first unequivocal synthesis of the base octahydroquinolizine, for an earlier attempted synthesis by Cierno and Ramage (33), involving a Clemmensen reduction of l-ketooctahydroquinolizine, led to the isomer l-azabicyclo[0.3.51decane. The latter was also synthesized unambiguously following the abovementioned procedure (99).…”

Section: Emetinementioning

confidence: 99%

The Chemistry of Quinolizines.

Thyagarajan¹

1954

Chem. Rev.

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I n der Folge haben wir uns einer weiteren Oniurn-Komponente mit 2 orthostandigen aktiven Methylengruppen zugewandt, namlich N -Me t hyle n -a -p i c oliniumsalzen (IV) und davon abgeleiteten Derivaten, deren Kondensation mit 1,2-Diketonen unter geeigneten Bedingungen in guter Ausbeute zu 2,3-disubstitu-ierten D e h y dr o -c hi n oli z i ni u ms a 1 z e n (V) f iihrt : VIII mit Phenanthrenchinon, die sich glatt vollzieht und zu 2,3,9',10'-Phenanthrodehydrochinoliziniumbromid (IX) fuhrt. OCH,Der Konstitutionsbeweis fur die erhaltenen Dehydrochinolizinium-Verbindungen wurde u. a. dadurch erbracht, da13 wir die oben genannte Verbindung I X mit Platin katalytisch zu D,L-2,3,9',10'-Phenanthrochinolizidin (X) vom Schmelzpunkt 170" hydrierten. Diese Substanz stellt das Grundgeriist des Cryptopleurins W e a t p h a l , J a n n und H e f f e 41Verwendet man hohere 1 ,a-Diketone wie Phenanthrenchinon, so erhalt man bei der Kondensation mit N-Carblthoxymethyl-l-methyl-isochinoliniumbroniid in e i n e r S t u f e das sechsfach annellierte Ringsystem des 2,3-9',10'-Phenanthro-S,9-benzo-dehydro-chinoliziniumbromids (XVI). Das R i n g s y s t e m des Chinolizins f i n d e t sich i n der N a t u r weitv e r b r e i t e t in F o r m zahlreicher, d a r u n t e r a u c h pharmakologisch hochwir ksamer Alkaloide. Das hier beschriebene Synthese-Prinzip mag dazu Die Kondensation von

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Über die Konstitution des sogenannten Norlupinans B

Cited by 23 publications

References 3 publications

A Novel and Efficient Total Synthesis of Cephalotaxine

A Novel and Efficient Total Synthesis of Cephalotaxine

The Chemistry of the Pyrrocolines and the Octahydropyrrocolines.

The Chemistry of Quinolizines.

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