Discovery of novel and potent aryl diamines as leukotriene A4 hydrolase inhibitors.

The synthesis and biological evaluation of a series of aryl diamines as inhibitors of LTA(4)-h inhibitors are described. The optimization which led to the identification of the optimal para-substitution on the diphenyl ether moiety and diamine spacer is discussed. The resulting compounds such as 3l have excellent enzyme and cellular potency as well as desirable pharmacokinetic properties.

Synthesis of N-alkyl glycine amides as potent inhibitors of leukotriene A4 hydrolase.

The synthesis and biological evaluation of a series of N-alkyl glycine amide analogs as LTA(4)-h inhibitors and the importance of the introduction of a benzoic acid group to the potency and pharmacokinetic parameters of our analogs are described. The lead compound in the series, 4q, has excellent potency and oral bioavailability.

Ammonia-promoted fragmentation of 2-alkyl- and 2,4-dialkyl-3-iodo-1- oxocyclohexan-2,4-carbolactones.

2-Alkyl- and 2,4-dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones undergo ammonia-promoted fragmentation reactions to provide butenolides, gamma-butyrolactone, and/or beta,gamma-epoxycyclohexanones. Product distribution is governed by the relative size of the substituents at C-2 and C-4 of the cyclohexanones. Butenolide amide, the major product from the fragmentation, is further converted into their respective piperidinone and pyrrolidine derivatives.

Novel fragmentation reaction of 2-alkyl- and 2,4-dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones.

2-Alkyl- and 2,4-dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones undergo lithium hydroxide- and lithium alkoxide-induced fragmentation reactions to provide butenolides, gamma-hydroxycyclohexenones, and/or gamma-butyrolactones. In general, product distribution is governed by two factors: (1) the nature of nucleophiles and (2) the steric bulkiness of the substituents at C-2 and C-4 of the cyclohexanones. Lithium hydroxide-induced fragmentation provides butenolides and gamma-hydroxycyclohexenones. In contrast, lithium alkoxide-promoted fragmentation results in predominantly 5-substituted gamma-butyrolactones along with a small amount of butenolides in limited cases. Fragmentation products induced by lithium hydroxide are largely influenced by the steric bulkiness of the substituents at C-2 and C-4 of the cyclohexanone ring. The bulky substituents render the exclusive formation of butenolides.

Synthesis of (-)-9,10-epi-stemoamide.

An efficient synthesis of (-)-9,10-epi-stemoamide has been accomplished in nine steps and 13% overall yield. The synthesis features a lithium hydroxide-promoted fragmentation and an intramolecular 7-exo-trig radical cyclization.

Synthesis and biological evaluation of menthol-based derivatives as inhibitors of plasminogen activator inhibitor-1 (PAI-1).

Compound 1 was identified by high throughput screening as a novel PAI-1 inhibitor. Optimization of the B and C-segments of 1 resulted in a series of structurally simplified compounds with improved potency. The synthesis and SAR data of these compounds are presented here.

An Oxidative Mannich Cyclization Methodology for the Stereocontrolled Synthesis of Highly Functionalized Piperidines.

Studies focusing on the development and application of a new oxidative methodology for promoting Mannich cyclizations have been conducted. The general features of these processes were explored with selected alpha-silylamino and alpha-silylamido allyl- and vinylsilanes. Representative conditions for affecting conversion of the alpha-silylamine and -amide functionalities into intermediate N-alkyl and N-acyliminium cations involve either 9,10-dicyanoanthracene SET-sensitized photooxidation or ceric ammonium or tetra-n-butylammonium nitrate oxidations. The applicability of these procedures for promoting Mannich cyclizations was first demonstrated by the preparation of methylidenepiperidines and -hydroazepines. Further studies have led to observations which show that Mannich cyclizations of stereochemically labeled alpha-silylamino vinylsilanes proceed to furnish tetrahydropyridines. Also, unlike their amine analogues, alpha-silylamido (E)-vinylsilanes undergo cyclization to produce tetrahydropyridines with retention of absolute and relative stereochemistry. The differences are due to the fact that N-acyliminium cations serve as intermediates in reactions of the alpha-silylamide systems. Moreover, the oxidation procedure is ideally suited for intermediate N-acyliminium cation generation in stereocontrolled reactions of alpha-silylamido allylsilanes. Finally, the preparative utility of the new cyclization method, when used in conjunction with an alpha-amino acid based strategy for substrate generation, was demonstrated by applications in concise routes for the synthesis of the aza-sugars, (-)-1-deoxymannojirimycin and (+)-1-deoxyallonojirimycin.