Enchaînements hétéroatomiques et leurs produits de cyclisation. VI. Nouvelle synthèse de céphèmes: acétyl-3 méthyl-7 phtalimido-7 oxo-8 thia-5 aza-1 bicyclo[4.2.0]octènes-2 diastéréomères

1983 ◽  
Vol 61 (6) ◽  
pp. 1169-1175 ◽  
Author(s):  
Jean-Claude Rozé ◽  
Jean-Paul Pradere ◽  
Guy Duguay ◽  
André Guevel ◽  
Hervé Quiniou ◽  
...  
Keyword(s):  
Double Bond ◽  
Total Synthesis ◽  
Cycloaddition Reaction ◽  
Thiazine Ring ◽  
Nitrogen Double Bond

The total synthesis of two diastereomeric cephems is described with three original steps in excellent yields: construction of the 1,3-thiazine ring via a (4+2) cycloaddition reaction, regioselective hydrogenation of the carbon–nitrogen double bond, and lactamization using BOP.

Configuration stability at the carbon-nitrogen double bond

1962 ◽  
Vol 3 (26) ◽  
pp. 1269-1274 ◽  
Author(s):  
D.Y. Curtin ◽  
C.G. McCarty
Keyword(s):  
Double Bond ◽  
Nitrogen Double Bond

scholarly journals Stereoselective total syntheses of (±)-sinularene and (±)-5-epi-sinularene: a general intramolecular Diels–Alder approach to tricyclic sesquiterpenes

1985 ◽  
Vol 63 (4) ◽  
pp. 993-995 ◽  
Author(s):  
Kazimierz Antczak ◽  
John F. Kingston ◽  
Alex G. Fallis
Keyword(s):  
Double Bond ◽  
Methyl Ester ◽  
Total Synthesis ◽  
Ring System ◽  
Diels Alder ◽  
Exocyclic Double Bond ◽  
Total Syntheses ◽  
Methyl Group ◽  
Secondary Hydroxyl ◽  
Selective Hydrogenolysis

Stereoselective total synthesis of (±)-sinularene and (±)-5-epi-sinularene are described. The sequence employs a "blocked" cyclopentadiene in which the cyclopropane unit also serves as a latent methyl group. Thus intramolecular [4 + 2] cycloaddition of the substituted methyl spiro[2.4]hepta-4,6-dien-1-yl)-2-pentenoate 11 affords 5-benzyloxy-6-isopropyl-8-carbomethoxytetracyclo[5.4.01,7.02,4.02,9]undec-10-ene (12) which after selective hydrogenolysis generates the tricyclo[4.4.01,6.02,8]decane (sinularene) ring system. Removal of the secondary hydroxyl function (Ph3P/CCl4/CH3CN; H2/Pd/C), reduction of the methyl ester (LiAlH4), and introduction of the exocyclic double bond (acetate pyrolysis, 550 °C) completes the synthesis of (±)-sinularene in 14 steps from cyclopentadiene. A parallel series of reactions employing the isopropyl epimer of 12 affords (±)-5-epi-sinularene.

Mechanisms of Nucleophilic Attack at Carbon Nitrogen Double-Bonds: The Reaction of Benzohydrazonoyl Halides With Amines

1987 ◽  
Vol 40 (10) ◽  
pp. 1777 ◽  
Author(s):  
AF Hegarty ◽  
P Rigopoulos ◽  
JE Rowe
Keyword(s):  
Double Bond ◽  
Nucleophilic Attack ◽  
Rate Data ◽  
Double Bonds ◽  
Nitrogen Double Bond

Rate data for the reaction of a series of benzohydrazonoyl halides with pyrrolidine and butan- 1-amine at 303 K are presented. Linear Hammett plots were obtained with each amine. The mechanism of the reactions and the stereochemical outcome of these displacements at the carbon-nitrogen double bond are discussed.

Total synthesis of barbatane sesquiterpenes: α- and β-barbatenes, gymnomitrol, and isogymnomitrol

1979 ◽  
Vol 57 (24) ◽  
pp. 3343-3345 ◽  
Author(s):  
Mitsuaki Kodama ◽  
Toshio Kurihara ◽  
Jinko Sasaki ◽  
Shô Itô
Keyword(s):  
Total Synthesis ◽  
Cycloaddition Reaction ◽  
Skeletal Rearrangements

A total synthesis of the barbatenes and a formal total synthesis of gymnomitrol and isogymnomitrol were achieved through a common intermediate utilizing a cycloaddition reaction and skeletal rearrangements.

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