Current Organic Chemistry - Volume 4, Issue 2, 2000

The isolation, structure determination and biological evaluation of the eudistomin alkaloids, isolated mainly from marine tunicates of the genus Eudistoma, is described. The compounds are placed in a well defined unique structural class based upon biogenic considerations. The methods which have been employed towards total synthesis of these metabolites are reviewed in detail.

Porphyrins, usually as metal complexes of either iron or magnesium, are widely distributed in nature, and exist as the prosthetic groups in a wide variety of primary metabolites such as hemoglobins, myoglobins, cytochromes, catalases, peroxidases, chlorophylls, and bacteriochlorophylls. This article describes the current best methodology for preparation of simple, symmetrical model porphyrins, as well as more complex proto Read More

The Pummerer rearrangement has been widely studied and has received considerable attention as a synthetically useful process. a-Acyl thionium ions generated from a-acyl sulfoxides under Pummerer conditions are powerful electrophiles, reacting efficiently with nucleophilic carbon species. Bimolecular addition of the cation to various carbon-carbon double bonds is well known. In the realm of natural product synthesis, most Read More

We describe how pyrrole derivatives derived from naturally occurring a-amino acids, and β-amino acids prepared from aspartic acid, can be efficiently converted into enantiomerically pure indolizidines by application of a three-part method. First, an optically pure, correctly substituted amino acid is condensed with tetrahydro-2,5-dimethoxyfuran to give the corresponding 1-pyrrolylacetic acid derivative. Second, through Read More

In this review we describe the asymmetrization of readily available Cs-symmetric compounds by enzyme-catalyzed reactions to provide chiral building blocks for the effective enantioselective synthesis of certain indole and quinolizidine alkaloids. By the asymmetrization of 1,2-disubstituted cyclo cyclohex-4-enes a series of class I alkaloids, such as (-)-antirhine, (-)-akagerine, and (posative)-meroquinene, have been synthesiz Read More