Using an atropdiastereoselective oxidative biaryl coupling as the key step, the total synthesis of the ellagitannin natural product sanguiin H-5 is reported. Both organomagnesium and organozinc based metalation methodologies were used to efficiently construct the strained medium-ring core of the natural product.

Abelian differentials on Riemann surfaces can be seen as translation surfaces, which are flat surfaces with cone-type singularities. Closed geodesics for the associated flat metrics form cylinders, whose number under a given maximal length generically has quadratic asymptotics in this length. Siegel–Veech constants are coefficients of these quadratic growth rates, and coincide for almost all su...

in order to gain a better understanding of the chemistry of methanl-to-hydro-carbon conversion, it is necessary to determine the nature of the primary reaction products. experiments carried out in this work on h-zsm-11, using a continuous flow reactor linked to an on-line gas chromatograph demonstrated that ethylene and methane are the primary reaction products. the results obtained using solid...