Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

Brønsted acid-mediated cyclization–dehydrosulfonylation/reduction sequences: An easy access to pyrazinoisoquinolines and pyridopyrazines

An efficient and alternative synthetic approach has been developed to prepare various N-(arylethyl)piperazine-2,6-diones from 4-benzenesulfonyliminodiacetic acid and primary amines using carbonyldiimidazole in the presence of a catalytic amount of DMAP at ambient temperature. Piperazine-2,6-diones are successfully transformed to pharmaceutically useful pyridopyrazines or pyrazinoisoquinolines a...

Easy access to antifungal agents.

Vulvovaginal candidiasis is a common problem; at one time or another most women experience at least one episode of this bothersome condition. For the past several years, the pharmaceutical industry has convinced women that this condition is easily treated and that they should recognize the symptoms of vulvovaginal candidiasis. Thus women have had access to a variety of intravaginal antifungal a...

On Reducing sequences and an Application to Local Cohomology Modules

Combined Lewis acid and Brønsted acid-mediated reactivity of glycosyl trichloroacetimidate donors.

Biomimetic conditions for a synthetic glycosylation reaction, inspired by the highly conserved functionality of carbohydrate active enzymes, were explored. At the outset, we sought to generate proof of principle for this approach to developing catalytic systems for glycosylation. However, control reactions and subsequent kinetic studies showed that a stoichiometric, irreversible reaction of the...

Easy access to modified cyclodextrins by an intramolecular radical approach.

A simple method to modify the primary face of cyclodextrins (CDs) is described. The 6(I)-O-yl radical of α-, β-, and γ-CDs regioselectively abstracts the H5(II), located in the adjacent D-glucose unit, by an intramolecular 1,8-hydrogen-atom-transfer reaction through a geometrically restricted nine-membered transition state to give a stable 1,3,5-trioxocane ring. The reaction has been extended t...