Total Synthesis of the Bacterial ortho-Quinol (+)-Strepantibin A through Iodyl-Type λ5-Iodane-Promoted Asymmetric Hydroxylative Phenol Dearomatization.

An enantioselective synthesis of the bacterial metabolite (+)-strepantibin A, a novel inhibitor of the hexokinase II (HK2) in cancer cells, is described. Its monomethylated resorcinolic para-terphenyl core was conveniently prepared through a Danheiser benzannulation. The elaboration of its ortho-quinolic chiral center was accomplished by relying on an iodyl-promoted regio- and enantioselective hydroxylative dearomatization. The olefinic side-chain of the resulting ortho-quinol was finally oxygenated under Wacker-type conditions to generate the propanone appendage of (+)-strepantibin A.

Experimental measurement of the wake field in a plasma filament created by a single-color ultrafast laser pulse.

A laser plasma wake field in a single-color femtosecond laser filament determines the acceleration of ionized electrons, which affects the intensity and bandwidth of the emitted terahertz wave and is important for understanding the fundamental nonlinear process of THz generation. Since the THz wave generated by a laser wake field is extremely small and easily hidden by other THz generation mechanisms, no method exists to measure this wake field directly. In this paper, a simple and stable method for determining the amplitude of the laser plasma wake field is presented. Based on the cancellation of a positive laser plasma wake field and an external negative electric field, the "zero point" of the intensity of the generated THz wave at some frequency can be used to determine the exact amplitude of the corresponding laser plasma wake field. This finding opens an avenue toward the clarification of ultrafast electronic dynamic processes in laser-induced plasmas.