Preparation of highly substituted pyrrolidines (proline analogs) was achieved by solid-phase organic synthesis using a three component 1,3-dipolar cycloaddition of a resin bound azomethine ylide. The synthesis utilizes a series of hydroxybenzaldehydes attached to Wang's resin via a Mitsunobu coupling followed by reaction with an alpha-amino ester and a maleimide. The solid phase reaction is utilized to obtain 3a as a single component. Alternatively, the reaction may be performed using an equimolar mixture of resins to afford a defined product mixture 4a-i as determined by LC-MS analysis.

Chiral pyrazole phenyl ethers (PPE) are highly active herbicides which are resolved by direct high-performance liquid chromatography on commercially available chiral stationary phases derived from N-3,5-dinitrobenzoyl derivatives of α-amino acids or amines (Whelk-O 1). The chromatographic data for a series of PPEs is presented and the structure-enantioselectivity comparisons are made for three different chiral stationary phases. Chromatographic resolution obtained is suitable for determination of enantiomeric purities and, in some cases, for preparative resolution of the enantiomers. By collection of material from repetitive chromatographic runs using an automated preparative system, suitable quantities for whole plant biological evaluation of both enantiomers of 2-[5-[[4-chloro-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]oxy]-2-nitrophenoxy]-N-methyl-butanamide were obtained in greater than 99% enantiomeric purity.

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An effective synthesis of N-substituted 2,4-diaminobutyric acids is described involving reaction of amines with methyl 4-bromo-2-phthalimidobutyrate, followed by hydrolysis. This approach was applied to the synthesis of 4-N-phosphonomethyl-2,4-diaminobutyric acids as inhibitors of glutamine synthetase.