152375-27-4

Usage

Structure

Fused pentagon and hexagon ring structure containing a pyridine ring

Molecular weight

163.25 g/mol

Stereoisomers

Mixture of stereoisomers with the (S)-enantiomer mentioned

Potential applications

Medicinal chemistry and drug development
Further research needed to fully understand properties and potential uses

Upstream product

• 64847-88-7 2-ethylcyclopentanone 
• 152266-60-9 (S)-(+)-2-ethyl-2-2'-carboxymethyl-ethylcyclopentanone 
• 152266-63-2 3-((S)-6-Ethyl-1,4-dioxa-spiro[4.4]non-6-yl)-propylamine 
• 118895-49-1 (+/-)-2-ethyl-2-(2'-cyanoethyl)cyclopentanone 
• 152266-61-0 3-((S)-6-Ethyl-1,4-dioxa-spiro[4.4]non-6-yl)-propionic acid methyl ester 
• 152266-62-1 3-((S)-6-Ethyl-1,4-dioxa-spiro[4.4]non-6-yl)-propionamide 

Relevant academic research and scientific papers

Formal synthesis of (-)-vallesamidine a 2,2,3-trialkylindoline alkaloid

(S)-(+)-2-ethyl-2[2'-carboxymethyl]cyclopentanone 6 was prepared regio- and enantioselectively (ee = 90%) by 'deracemizing alkylation' of the chiral imine 5 with methylacrylate. Compound 6 was transformed into the bicyclic imine (R)-(+)-3. This intermediate was used by Heatcock, in the racemic form, to the total synthesis of (±)-Vallesamidine 1, a 2,2,3-trialkylindoline alkaloid.

Total Synthesis of (+/-)-Vallesamidine

This article reports full details of a project aimed at providing synthetic access to the 2,2,3-trialkylindoline alkaloids such as vallesamidine (4).The basic strategy was to preassemble the tricyclic portion containing the nonindolic nitrogen and to form the indoline ring at a late stage in the synthesis.An approach summarized in the retrosynthetic analysis summarized in Scheme III failed because enones 48 and 50 do not undergo 1,4-addition of nitrogen nucleophiles.However, the retrosynthesis summarized in Scheme X did lead to a sucessful synthesis of (+/-)-4.Thesynthesis requires seven steps from 2-ethylcylopentanone 54 -> 56 -> 66 -> 68 -> 71 -> 74 -> (+/-)-4> and delivers the alkaloid in 19percent overall yield.Pivotal steps in the synthesis are the lactam annelation process in which 56 reacts with o-nitrocinnamic acid to yield 66 and the NBS-mediated cyclization of amino lactam 68 to the pentacyclic bromo lactam 70.Four of seven steps involve the formation of skeletal (C-C or C-N) bonds and only three are functional-group transformations.