Francesca Cardullo

Cyclative cleavage via solid-phase supported stabilized sulfur ylides: synthesis of macrocyclic lactones

A new synthesis of macrolactones bearing a cyclopropyl ring condensed to the macrocycle is reported via a cyclization-release strategy making use of solid-phase supported stabilized sulfur ylides.

Synthesis and Structure-Activity Relationships of α-Amino-γ-lactone Ketolides: A Novel Class of Macrolide Antibiotics.

An efficient synthesis of α-amino-γ-lactone ketolide (3) was developed, which provided a versatile intermediate for the incorporation of a variety of aryl and heteroaryl groups onto the C-21 position of clarithromycin via HBTU-mediated amidation. The biological data for this important new class of macrolides revealed significantly potent activity against erythromycin-susceptible strains as well as efflux-resistant and erythromycin MLSB-resistant strains of S. pneumoniae and S. pyogenes. In addition, ketolide 11o showed excellent in vitro antibacterial activity against H. influenzae strain as compared to telithromycin. These results indicate that C-21 substituted γ-lactone ketolides have potential as a next generation macrolide antibiotics.

Rapid Access to 1-Benzyl 2-Substituted Piperazines: Application to the Synthesis of 1-Benzyl-2-difluoromethyl-Piperazine

Abstract A rapid and efficient synthesis of 1-benzyl-2-difluoromethyl-piperazine is herein described. The new pathway has the advantage of avoiding orthogonal protection at the two piperazine nitrogen atoms; therefore it is suitable for access to several 1-benzyl 2-substituted piperazines starting from the simple commercially available N,N′-dibenzylethylendiamine.