237421-53-3

Upstream product

• 91229-91-3 tert-butyl (S)-N-tert-butoxycarbonylpyroglutamate 
• 106-95-6 allyl bromide 

Downstream Products

• 87679-37-6 trandolapril 
• 237421-60-2 tert-butyl (2S,4S)-N-tert-butoxycarbonyl-4-(2-oxo-3-O-tert-butyldiphenylsilyloxypropyl)-pyroglutamate 
• 237421-58-8 tert-butyl (2S,4S,7RS)-4-(2-hydroxy-3-O-tert-butyldiphenylsilyloxypropyl)-pyroglutamate 
• 237421-59-9 tert-butyl (2S,4S)-4-(2-oxo-3-O-tert-butyldiphenylsilyloxypropyl)-pyroglutamate 

Relevant academic research and scientific papers

A Stereoselective Synthesis of the ACE Inhibitor Trandolapril

A conceptually novel and stereoselective synthesis of the enantiopure octahydroindole building block and its conversion into the ACE inhibitor trandolapril was achieved. Key steps include the α-allylation of a protected l -pyroglutamic acid derivative, a highly diastereoselective Hosomi-Sakurai reaction and a Ru-catalyzed ring-closing metathesis of a 4,5-diallylated proline. This way, the synthesis of trandolapril was efficiently achieved in 25% overall yield (12 steps).

Design and Synthesis of Building Blocks for PPII-Helix Secondary-Structure Mimetics: A Stereoselective Entry to 4-Substituted 5-Vinylprolines

In the course of our studies towards the synthesis of proline-based secondary-structure mimetics, we developed a straightforward methodology for the diastereoselective preparation of 4-alkyl-5-vinyl-substituted proline derivatives. Starting from N-Boc-protected tert-butyl pyroglutamate, α-alkylation, lactam reduction and acid-catalyzed methanolysis afforded 4-alkyl-5-methoxyproline derivatives. After BF3-induced formation of an N-acyl-iminium intermediate, the introduction of the 5-vinyl side chain was achieved with high diastereoselectivity by using vinylmagnesium bromide in the presence of AlCl3 or CuBr·SMe2 to afford either the cis- or the trans-product, respectively. The utility of the method was demonstrated in the rapid and efficient construction of new diproline mimetics rigidified in a polyproline-type II helix (PPII) conformation.

Versatile synthesis of inhibitors of late enzymes in the bacterial pathway to lysine

Modification of our 'ring switching' reaction has allowed us to develop a versatile synthesis of potential inhibitors of the late enzymes in the bacterial pathway to lysine. The methodology is applicable to solid phase combinatorial synthesis.