73376-35-9

Upstream product

• 131636-08-3 methyl 2-<(S)-N-<(R)-α-methylbenzyl>pyrrolidin-2-yl>propenoate 
• 132151-88-3 R-(-)-2-methylhexanal 
• 131636-12-9 (8aS)-8-methyleneoctahydro-5-indolizidinone 
• 131636-11-8 ethyl 4-<(S)-N-<(S)-α-methylbenzyl>pyrrolidin-2-yl>-4-pentenoate 
• 131636-13-0 (8S,8aS)-8-Hydroxy-6-((R)-1-hydroxy-2-methyl-hexyl)-8-methyl-hexahydro-indolizin-5-one 
• 131636-10-7 N-<(S)-α-methylbenzyl>-2-(S)-<1-(hydroxymethyl)ethenyl>pyrrolidine 
• 131636-14-1 (8S,8aS)-8-hydroxy-8-methyl-6(Z)-<2(R)-methylhexylidene>octahydro-5-indolizidinone 
• 131722-93-5 (5R,6S)-5-hydroxy-5-methyl-1-azabicyclo[4.3.0]nonane-2-one 
• 66050-98-4 (2R)-methyl-1-hexanol 

Relevant academic research and scientific papers

Total synthesis of pumiliotoxins 209F and 251D via late-stage, nickel-catalyzed epoxide-alkyne reductive cyclization

(Chemical Equation Presented) Pumiliotoxins 209F and 251D were synthesized using highly selective nickel-catalyzed epoxide-alkyne reductive cyclizations as the final step. The exocyclic (Z)-alkene found in the majority of the pumiliotoxins was formed ster

Total synthesis of (+)-pumiliotoxin 251D

The convergent total synthesis of pumiliotoxins by attachment of the side chain to a suitably functionalized core indolizidinone derivative has been achieved. The use of an aldoltype addition condensation strategy, intended to provide for the stereoselective generation of the exocyclic double bond, gave no satisfactory results. The method of choice was a Homer olefination. Initially, the reactant core indolizidinone was converted into an α phosphono amide by amide enolate formation, enol phosphate generation, and a final phosphatephosphonate migration. The amido phosponates smoothly underwent Horner-type olefinations to allow successful introduction of the side chain with high Z selectivity in the exocyclic double bond. Similarly, the introduction of the phosphonate and the subsequent olefination could be run as a one-pot process. The final reductive removal of the lactam function provided (-)-8-epi-pumiliotoxin 209 F and (+)-pumiliotoxin 251 D. The structure of the pumiliotoxin 251 D was confirmed by X-ray analysis. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.

Toxicity of Pumiliotoxin 251D and Synthetic Analogs to the Cotton Pest Heliothis virescens

A series of 13 simplified analogs of frog skin derived pumiliotoxin indolizidine alkaloids was prepared and evaluated for their toxicity to the larvae of the important cotton pest Heliothis virescens.The alkyl side chain of pumiliotoxin 251D was replaced with a variety of substituents designed to influence or restrict its conformation and its ability to act as a site of metabolic detoxification.Significantly, a substituent in the R configuration at the C-2' carbon of the side chain was required for toxicity.Computational studies suggested that this substituent may control the active conformation of the side chain.No structural modification led to a significant improvement in toxicity over the natural product.Keywords: Pumiliotoxin; insecticide; Heliothis virescens; structure-activity

Enantioselective synthesis of pumiliotoxin 251D. A strategy E employing an allene-based electrophile-mediated cyclization

The enantioselective synthesis of pumiliotoxin 251D (1) (nine steps, 6.3% overall yield) is described in which the Pd11-mediated cyclization of the optically pure allenic amine 6 to give pyrrolidine 7a plays a central role. The functionality th