Many D2d-symmetric 2,2',6,6'-tetrasubstituted biphenyls are
readily prepared via net oxidative dimerization of appropriate
1,3-disubstituted benzenes. Conversion of such proprochiral
compounds to useful C2-symmetric chiral biphenyls requires
formal replacement of two substituents on opposing aryl ring
units with alternate groups. This under exploited
desymmetrization tactic has been demonstrated for the
generation...
An automated multielement flame atomic fluorescence (AF) spectrometer based on microcomputer control was constructed to determine four elements simultaneously. The instrument employs a multiple exit slit monochromator where the light from various exit slits is directed to a single detector with a mirrored funnel. Each element is excited to fluoresce...
Studies towards the total synthesis of (+)-Phomactin A (1), D (6), and G (9), fungal metabolites with unique molecular architecture and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediates 354 and 356, which contain all of the carbon atoms of 1, 6 and 9....
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
The analysis of 64 rock samples from Saudi Arabia and three
samples from the axial trough of the Red Sea has been done.
Instrumental neutron activation analysis (INAA) was the analytical
tool used for the analysis of at least 18 and as many as 24 elements
in these 67 rock...
An automated instrument based on a single-board microcomputer
was developed for use in voltammetric analyses. Operator input of
numerous experiment parameters allows any type of voltammetric
analysis to be implemented and multiple scans to be run unattended.
A three operational amplifier potentiostat is used to control
the cell voltage and...