469-34-1

Upstream product

• 480-54-6 retrorsine 
• 22787-68-4 methyl 2-(1-acetoxyethyl)acrylate 
• 98837-36-6 methyl 3-hydroxy-2-methylenebutyrate 
• 106060-34-8 (+/-)-dimethyl retronecate 
• 33935-64-7 methyl 2-(bromomethyl)-2-butenoate 
• 106060-36-0 dimethyl 1,2-diacetoxy-3-methyl-5,6-epoxyheptane-2,5-dicarboxylate 
• 106060-35-9 dimethyl 3-methyl-5,6-epoxyhept-1-ene-2,5-dicarboxylate 
• 106060-37-1 dimethyl (E)-1,2-diacetoxy-3-methylhept-5-ene-2,5-dicarboxylate 
• 106060-27-9 4-(1-acetoxyethyl)-4-methoxycarbonyl-2,2-dimethyl-1,3-dioxolane 
• 106060-26-8 methyl 3-acetoxy-2-hydroxy-2-hydroxymethylbutanoate 
• 106060-28-0 4-(1-hydroxymethyl)-4-methoxycarbonyl-2,2-dimethyl-1,3-dioxolane 
• 106060-29-1 4-(1-chloroethyl)-4-methoxycarbonyl-2,2-dimethyl-1,3-dioxolane 
• 106060-38-2 dimethyl-1,2-dihydroxy-3-methyl-5,6-epoxyheptane-2,5-dicarboxylate 
• 106060-30-4 dimethyl 5-ethylidene-3-methyl-2-methylenehexane-2,5-dicarboxylate 

Relevant academic research and scientific papers

Pyrrolizidine Alkaloid Biosynthesis. Synthesis of 3H-Labelled Trachelanthamidine and Isoretronecanol and their Incorporation into Three Pyrrolizidine Bases (Necines)

(+/-)-Isoretronecanol (22) and (+/-)-trachelanthamidine (24) were prepared by 1,3-dipolar cycloaddition of N-formylproline with ethyl propiolate followed by reduction steps.These 3H-labelled 1-hydroxymethylpyrrolizidines together with putrescine were fed to Senecio isatideus which produces retrorsine (1); S. pleistocephalus which yields rosmarinine (8); and Cynoglossum officinale which affords echinatine (5).The double labelling experiments demonstrated that isoretronecanol is incorporated much more efficiently into rosmarinine than into retrorsine or echinatine, whereas trachelanthamidine is a much more efficient precursor for retrorsine and echinatine.Base hydrolysis of retrorsine and echinatine labelled with trachelanthamidine and of rosmarinine labelled with isoretronecanol established that most of the 3H-label was in the base portions, retronecine (2), heliotridine (6), and rosmarinecine (9), respectively.Further degradation of retronecine and rosmarinecine showed that most of the radioactivity was confined to the β-alanine (4) portion.The biosynthetic pathways to isoretronecanol and trachelanthamidine apparently diverge prior to the formation of these 1-hydroxymethylpyrrolizidines, probably during the cyclisation of an immonium ion (14) to form the 1-formylpyrrolizidines (15) and (17).

Necic Acid Synthons. Part 5. Total Synthesis of (+/-)-Retronecic Acid and Related Compounds via Zinc-Mediated Coupling of Halogeno-esters

Zinc-mediated coupling of suitably substituted halogeno esters affords access to (+/-)-retronecic acid (2) and related intermediates.These approaches lead to racemic retronecic acid on the one hand and to a diastereoisomeric mixture of the acid on the other.