Microbial hydroxylation/functionalization of terpenoid synthons derived from communic acids.

Incubation of a communic acid-derived synthon with Cunninghamella elegans quantitatively affords 1 beta, 3 beta- and 7 beta- monohydroxylated derivatives.

Microbial hydroxylation of natural drimenic lactones.

Incubation of confertifolin and isodrimenin with Mucor plumbeus, Aspergillus niger or Rhizopus arrhizus gave in good yields the corresponding 3 beta-hydroxy derivatives. From isodrimenin, the known natural 7 alpha-hydroxy derivative (futronolide) was also obtained and its structure was definitely established by X-ray crystallographic study of its acetate derivative.

Resolution of alpha-substituted amino acid enantiomers by high-performance liquid chromatography after derivatization with a chiral adduct of o-phthalaldehyde. Application to glutamic acid analogues.

The fluorescent diastereoisomeric adducts formed in a precolumn derivatization reaction of enantiomeric alpha-substituted amino acids with o-phthalaldehyde and N-acetyl-L-cysteine were separated by high-performance liquid chromatography on a conventional reversed-phase column. This method was particularly efficient for the complete analytical resolution of alpha-substituted glutamic acid analogues, such as 2-methylglutamic acid, and several cyclic analogues (1-amino-1,3-dicarboxycyclohexane, 1-amino-1,3-dicarboxy-2-cyclohexene and 1-amino-1,3-dicarboxycyclopentane). The order of elution from the column was correlated with the absolute configuration of the derivatives.