Synthesis of (–)-Indolizidine 167B based on domino hydroformylation/cyclization reactions

• Giuditta Guazzelli,
• Raffaello Lazzaroni and
• Roberta Settambolo

Beilstein J. Org. Chem. 2008, 4, No. 2, doi:10.1186/1860-5397-4-2

• multi-step domino reaction sequences which are a very convenient approach to complex architectures in one simple, safe, environmentally acceptable and resource-effective operation [12][13][14]. The mechanistic as well as synthetic implications of the oxo reaction involving vinyl and allyl aromatic and

• heteroaromatic olefins has a topic of our research for many years [15][16][17][18][19]; now it is the first time that the rhodium catalyzed hydroformylation is employed by us in the total synthesis of a target compound and as a key reaction in a domino process with a high number of steps. Results and Discussion

• describe here a new synthesis of optically active (–)-Indolizidine 167B based on regioselective hydroformylation/intramolecular cyclization reactions which provides a general approach to the indolizine nucleus. It is a multi-step domino process which starts with the interconversion of the isomeric rhodium

Desymmetrization of 7-azabicycloalkenes by tandem olefin metathesis for the preparation of natural product scaffolds

• Wolfgang Maison,
• Marina Büchert and
• Nina Deppermann

Beilstein J. Org. Chem. 2007, 3, No. 48, doi:10.1186/1860-5397-3-48

• RORCM conversions, because they may be desymmetrized either by diastereoselective or enantioselective metathesis. Results and Discussion In a first attempt to transfer the RORCM-strategy to 7-azabicycloalkenes, we chose 7 as a precursor for domino metathesis reactions. Our choice was due to the

An efficient synthesis of novel pyrano[2,3-d]- and furopyrano[2,3-d]pyrimidines via indium- catalyzed multi- component domino reaction

• Dipak Prajapati and
• Mukut Gohain

Beilstein J. Org. Chem. 2006, 2, No. 11, doi:10.1186/1860-5397-2-11

• Dipak Prajapati Mukut Gohain Department of Medicinal Chemistry, Regional Research Laboratory, Jorhat 785006, Assam, India 10.1186/1860-5397-2-11 Abstract Various novel pyrano [2,3-d]pyrimidines 5 and furopyrano [2,3-d]pyrimidines 7 were synthesized in 80–99% yields via a multicomponent domino

• reaction of α,β-ethylenic ketones and ethyl vinyl ether or 2,3-dihydrofuran has remained unexplored.[11] Herein, we report the first example of indium(III) chloride catalysed synthesis of fused pyrimidine derivatives via a multicomponent domino Knoevenagel hetero Diels-Alder reaction. The reaction proceeds

• comparable yields. The structure of all the products thus obtained were characterized by elemental and spectral analyses. Conclusion In conclusion, we have shown that the multicomponent domino Knoevenagel condensation/hetero-Diels-Alder reaction of aromatic aldehydes with 1,3-dimethylbarbituric acid and