Asymmetric total synthesis of (-)-quinocarcin.

(-)-Quinocarcin (1) has been synthesized in a longest linear sequence of 22 steps from 3-hydroxybenzaldehyde in 16% overall yield. The Pictet-Spengler reaction of L-tert-butyl-2-bromo-5-hydroxy phenylalanate (17), synthesized according to Corey-Lygo's enantioselective alkylation process, with benzoxyacetaldehyde (12) under mild acidic conditions afforded 1,3-cis tetrahydroisoquinoline 20 as an only isolable stereomer in 91% yield. The diazabicycle[3,2,1]-octane ring system of 28 was constructed by a silver tetrafluoroborate-promoted intramolecular Mannich reaction using amino thioether as a latent N-acyliminium species and tethered silyl enol ether as a nucleophile.

Protein electrophoretic markers in Israel: compilation of data and genetic affinities.

Background: A considerable body of data has been accumulated since the 1960s on protein electrophoretic markers in the Jewish populations of Israel. However, in some Jewish communities and for some markers insufficient information has been available. In addition, studies that tried to explore the genetic affinities of various Jewish populations mainly employed antigenic markers and frequently used a small and unrepresentative number of non-Jewish populations as comparisons.