1724-18-1

Upstream product

• 186581-53-3 diazomethane 
• 1724-17-0 oleanolic acid methyl ester 
• 60-29-7 diethyl ether 
• 10026-13-8 phosphorus pentachloride 
• 22425-82-7 methyl maslinate 
• 508-02-1 Oleanolic acid 
• 557765-95-4 C₃₁H₄₈O₆S 
• 292859-56-4 methyl 2α-tosyloxy-3β-hydroxy-12-oleanen-28-oate 
• 292859-65-5 methyl 2β,3β-epoxy-12-oleanen-28-oate 

Downstream Products

• 211516-63-1 (3aR,5aR,5bS,7aS,11aS,13aR,13bR)-5a,5b,10,10,13b-Pentamethyl-3-oxo-1,2,3,3a,4,5,5a,5b,6,7,8,9,10,11,11a,13,13a,13b-octadecahydro-cyclopenta[a]chrysene-7a-carboxylic acid methyl ester 

Relevant academic research and scientific papers

Epoxides, cyclic sulfites, and sulfate from natural pentacyclic triterpenoids: Theoretical calculations and chemical transformations

Several triterpenic derivatives, with the A-ring functionalized, were semisynthesized from oleanolic and maslinic acids. The reactivities of sulfites, sulfate, and epoxides in these triterpene compounds were investigated under different reaction conditions. Moreover, contracted A-ring triterpenes (five-membered rings) were obtained, by different treatments of the sulfate 7. From the epoxide 8, deoxygenated and halohydrin derivatives were semisynthesized with several nucleophiles. Ozonolysis and Beckmann reactions were used to yield 4-aza compounds, from five-membered ring olanediene triterpenes. The X-ray structure of sulfate 7 is given and compared with density functional theory geometries. Theoretical 13C and 1H chemical shifts (gauge-invariant atomic orbital method at the B3LYP/6-31G*//B3LYP/6-31G* level) and 3JH,H coupling constants were calculated for compounds 5-9 and 34-36, identifying the (R)- or (S)-sulfur and α- or β-epoxide configurations together with 4-aza or 3-aza structures.

Semi-synthesis of Triterpene A-Ring Derivatives from Oleanolic and Maslinic Acids. Theoretical and Experimental 13C Chemical Shifts

Oleanolic and maslinic acids were isolated from solid waste from olive oil and several derivatives were semi-synthesised using typical reaction procedures. Rearrangements of methyl oleanate by mesylation or treatment with phosphorus pentachloride were accomplished. Six rearranged products were obtained from these reactions, three of which were 3(4) -> 5-abeo compounds formed by A-ring contraction of the oleanene skeleton. Experimental 13C NMR chemical shifts for 21 compounds are given and a discussion of the substituent effects on their 13C shieldings are also included. Morover, theoretical 13C NMR chemical shifts, with the GIAO method calculated at the MM+ geometries using the B3LYP/6-31G* level, showed good agreement with the experimental, allowing a correct assignment for the experimental shifts.