Synthesis of the C4-epi-lomaiviticin B core reveals subtle stereoelectronic effects.

Enantioselective synthesis of the lomaiviticin aglycon full carbon skeleton reveals remarkable remote substituent effects during the dimerization event.

The cytotoxicity of (–)-lomaiviticin A arises from induction of double-strand breaks in DNA

The metabolite (-)-lomaiviticin A, which contains two diazotetrahydrobenzo[b]fluorene (diazofluorene) functional groups, inhibits the growth of cultured human cancer cells at nanomolar-picomolar concentrations; however, the mechanism responsible for the potent cytotoxicity of this natural product is not known. Here we report that (-)-lomaiviticin A nicks and cleaves plasmid DNA by a pathway tha...

Progress toward the total synthesis of psymberin/irciniastatin A.

In this paper, we describe our synthesis of four key building blocks for the total synthesis of psymberin (1) and its C4 epimer (2). Despite early difficulties in processing material to the advanced intermediate stage, we have been successful in developing high-yielding syntheses for the pyran core, natural side chain, 4-epi side chain, and aryl fragments of the molecule. Our findings from the ...

Spotlight: Catalytic vinylogous anomeric based oxidation (Part I)

Stereoelectronic effects is a bridge between structure and reactivity [1]. Anomeric effect plays an important role in the domain of stereoelectronic interaction and can be used for description of several unusual phenomena. Intramolecular negative hyperconjugation is also known as anomeric effect [2]. In anomeric effect, both donor (lone pairs) and acceptor groups (electronegative elements) coex...

A Theoretical Study on Applying Conformational Analysis of 2-Halo-2-Oxo-1,3,2-Dioxaphosphorinanes

The quantum-chemical calculations on the conformational properties of 2-flouro-2-oxo- 1,3,2-dioxaphosphorinane (1), 2-choloro-2-oxo-1,3,2-dioxaphosphorinane (2) and 2-bromo- 2-oxo-1,3,2-dioxaphosphorinane (3) have been investigated by means of ab initio molecular orbital (HF/6-311+G**) and hybrid density functional theory (B3LYP/6-311+G**) based methods and Natural Bond Orbital (NBO) interpreta...