Total Synthesis and Structural Verification of Some Novel Branched Alkanes with Quaternary Carbons Isolated from Diverse Geological Sources
摘要:
With a view to the authentication of an unusual series of branched alkanes with quaternary centers (BAQCs) isolated from geological samples, and whose structures rest on the interpretation of EI-mass spectral fragmentation patterns, the total synthesis of 3-ethyl-3-methylheptadecane, 3,3-dimethylheptadecane, 3,3,11,11-tetraethyltridecane, and 5,5,7,7-tetraethylundecane is described. The GC-MS data of the first two samples are identical with those of the isolates and confirm their structures. However, the GC-MS data of the two more highly branched structures do not match those of the geological isolates leading to the conclusion that these structures were erroneously assigned.
Differentiating CBr and CCl Bond Activation by Using Solvent Polarity: Applications to Orthogonal Alkyl-Alkyl Negishi Reactions
作者:Niloufar Hadei、George T. Achonduh、Cory Valente、Christopher J. O'Brien、Michael G. Organ
DOI:10.1002/anie.201100705
日期:2011.4.18
A pot to share: A CalkylClbond can be rendered “dormant” or “active” in the Negishialkyl–alkyl cross‐coupling by a simple solventpolarity “switch” (see scheme). Adjustment from a 1:2 to a 2:1 solvent ratio of dimethylimidazolidinone:tetrahydrofuran enables orthogonalalkyl–alkylNegishi cross‐coupling strategies to be carried out on bifunctional bromochloroalkanes in one pot at room temperature