The multi-step synthesis of complex organic compounds from simpler precursors is one of the outstanding accomplishments and ongoing challenges of synthetic organic chemistry. Through the development and invention of synthesis strategies, methods and technologies, increasingly complex molecules can be assembled with designed structures and functions for a variety of medicinal, agrochemical and m...

An expedient, practical, and enantioselective route to the highly congested ent-kaurane diterpene maoecrystal V is presented. This route, which has been several years in the making, is loosely modeled after a key pinacol shift in the proposed biosynthesis. Only 11 steps, many of which are strategic in that they build key skeletal bonds and incorporate critical functionalities, are required to a...

Experiences gained from the design of micro-kernel related to either high-performance or hard real-time computing have shown that customization plays a major role to enhance the performance of applications while maintaining a reusable and exible software architecture. Our goal is to cover both elds by developing a customizable library operating system (Dreams 1) intended to be used as a basis f...

In the post-genomic era, the ability to synthesize any arbitrary DNA sequence is increasingly in demand. A bottleneck in current gene synthesis technologies is the associated cost, due primarily to the high cost of oligonucleotides synthesis and post-synthesis sequencing. In the present paper, an improved method for low-cost gene synthesis that combines dual asymmetrical PCR and overlap extensi...

Chenodiol is an important bile acid widely used for gallstone dissolution and cholestatic liver diseases. We succeeded in a short-step synthesis of chenodiol, starting from the safer phytosterol, stigmasterol.

A one-step synthesis of two 5-CF(3) UDP-sugars is reported. These non-natural sugar-nucleotides are micromolar inhibitors of two different galactosyltransferases.

A concise route to a small family of exotic marine alkaloids known as the araiosamines has been developed, and their absolute configuration has been assigned. The dense array of functionality, high polarity, and rich stereochemistry coupled with equilibrating topologies present an unusual challenge for chemical synthesis and an opportunity for innovation. Key steps involve the use of a new reag...

Previous studies of the pathway of biosynthesis of diaminopimelic acid had indicated that pyruvic acid (1) and aspartic semialdehyde (2) were sources of the carbon skeleton of diaminopimelic acid. In addition, N-succinyl-cY-amino-e-ketopimelic acid had been established as an intermediary in the biosynthesis (3, 4). A comparison of the structures of these precursors and this intermediary (Fig. 1...

An enantioselective total synthesis of the Strychnos alkaloid (+)-minfiensine has been accomplished. Prominent features of this synthesis include (i) a new enantioselective organocatalytic Diels-Alder/amine cyclization sequence to build the central tetracyclic pyrroloindoline framework in four steps from commercial materials and (ii) a 6-exo-dig radical cyclization to forge the final piperidiny...