An Easy Transformation of Ketones into α,α-Epoxymethylketones by Hydrogen Peroxide Oxidation of Mannich Base Derivates

Hénin, Françoise; Pete, Jean‐Pierre

doi:10.1055/s-1980-29257

Cited by 13 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…29 The trans counterpart 2 was prepared from cyclohexanone by Mannich condensation with paraformaldehyde and dimethylamine hydrochloride. 30 The Mannich base was then subjected to Hofmann's exhaustive methylation, and epoxidation resulting in the epoxy ketone, which was reduced stereoselectively using sodium borohydride in MeOH to provide 2.…”

Section: Resultsmentioning

confidence: 97%

“…Syntheses of the 1-Aminomethylcyclohexane-1,2-diols 4 and 6. Diastereomeric cis - and trans -epoxy alcohols 1 and 2 were synthesized stereoselectively by a combination of literature methods. ,− The synthesis of cis -epoxy alcohol 1 started from ethyl 2-oxocyclohexanecarboxylate with LiAlH 4 reduction, followed by stereoselective epoxidation of the resulting 2-methylene-1-cyclohexanol with m -chloroperbenzoic acid . The trans counterpart 2 was prepared from cyclohexanone by Mannich condensation with paraformaldehyde and dimethylamine hydrochloride .…”

Section: Resultsmentioning

confidence: 99%

“…Diastereomeric cis - and trans -epoxy alcohols 1 and 2 were synthesized stereoselectively by a combination of literature methods. ,− The synthesis of cis -epoxy alcohol 1 started from ethyl 2-oxocyclohexanecarboxylate with LiAlH 4 reduction, followed by stereoselective epoxidation of the resulting 2-methylene-1-cyclohexanol with m -chloroperbenzoic acid . The trans counterpart 2 was prepared from cyclohexanone by Mannich condensation with paraformaldehyde and dimethylamine hydrochloride . The Mannich base was then subjected to Hofmann's exhaustive methylation, and epoxidation resulting in the epoxy ketone, which was reduced stereoselectively using sodium borohydride in MeOH to provide 2 .…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Formation and Characterization of a Multicomponent Equilibrium System Derived from cis- and trans-1-Aminomethylcyclohexane-1,2-diol

et al. 2003

View full text Add to dashboard Cite

Both cis and trans isomers of amino diols 3-6 were prepared stereoselectively. In the reactions between 3-6 and phenyl isothiocyanate, the ring closure proceeded regioselectively and resulted only in spiro derivatives of 2-phenyliminooxazolidines 9, 10, 13, and 14. The reaction of cis- (or trans-)1-aminomethylcyclohexane-1,2-diol 4 (or 6) with 1 equiv of an aromatic aldehyde 15a-g in EtOH at room temperature resulted in a complex, multicomponent equilibrium mixture of 16a-g and 18a-g (or 17a-g and 19a-g), in each case consisting of a five-component, ring-chain tautomeric system 16A-E (or 17A-E), involving the Schiff base, two epimeric spirooxazolidines, two epimeric condensed 1,3-oxazines, and some of the four tricyclic compounds 18A-D (or 19A-D). The five-component, ring-chain equilibria were found to be adequately described by the Hammett-Brown linear free energy equation.

show abstract

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Formation and Characterization of a Multicomponent Equilibrium System Derived from cis- and trans-1-Aminomethylcyclohexane-1,2-diol

et al. 2003

View full text Add to dashboard Cite

show abstract

“…Although there have been only a few literature reports involving exo-cyclic functionality in cycloheptanone, the cyclohexanone analogues have been widely reported. Many methods exist for the installation of the exo-cyclic double bond, including aldol chemistry, 40 the Mannich reaction, 41 and the use of Eschenmoser's salt to form activated α-cycloketones which can then undergo elimination to form methylidene cycloketones. These methods were attractive as the starting materials in these cases were readily available cycloketones (in our case cycloheptanone).…”

Section: Reactions: Results and Discussionmentioning

confidence: 99%

Cascade Approaches Towards the Synthesis of Daphnioldhanin A Alkaloid

Khan¹

View full text Add to dashboard Cite

<p>Daphnioldhanin A 1.6 is a recent alkaloid obtained from Daphyniphyllum plants. The core structure as shown consists of a 5,5,7 tricyclic ring system, which is a challenging ring system and to date has not been reported in any other natural product. This project focussed on using two cascade approaches in forming this ring system, namely radical addition and cyclisation cascade and carbene cycloaddition cyclisation cascade CCCC. Using the radical approach would require a 5-endo trig cyclisation, which is disfavoured by Baldwin's rules, but has been reported in systems which have an hetereoatom (carbonyl, nitrogen or sulfur) incorporated in the ring. In our case, the 5-endo trig cyclisation is needed in an all carbon containing ring, and preliminary modelling studies have shown that the energy for the 4-exo trig cyclisation product is higher than that of the 5-endo trig cyclisation product. Therefore, the radical approach if successful will eventuate in a novel 5-endo trig cyclisation in an all carbon system. However, due to stability issues with the radical precursors this method had to be abandoned and attention focused on the CCCC approach. For the CCCC approach, rhodium catalysed cascade cyclisation is intended on diazo compound 1.22. The presence of the intramolecular double bond enhances the second cyclisation to occur which will form the 5 and 7-membered ring simultaneously along with oxo-bridge resulting in the functionalised pentacyclic ring system which would be very similar to the proposed 5,5,7 core of Daphnioldhanin A. The desired diazo compound could not synthesised due to failure in forming the anhydride for the acid and future work would be focussed on forming acid derivatives in order to form the diazo compound 1.22 before using rhodium catalysed cyclisation to form the functionalised pentacyclic compound.</p>

show abstract