247200-06-2

Upstream product

• 98-59-9 p-toluenesulfonyl chloride 
• 247200-04-0 (E)-(4R,5R,8S,9R)-1-Benzyloxy-4,5-bis-(tert-butyl-dimethyl-silanyloxy)-9-methoxymethoxy-nonadec-10-en-8-ol 
• 204572-66-7 (4R,5R)-8-Benzyloxy-4,5-bis-(tert-butyl-dimethyl-silanyloxy)-octanal 
• 247200-05-1 Toluene-4-sulfonic acid (E)-(1S,2R)-1-[(3R,4R)-7-benzyloxy-3,4-bis-(tert-butyl-dimethyl-silanyloxy)-heptyl]-2-methoxymethoxy-dodec-3-enyl ester 

Downstream Products

• 102989-24-2 (+)-asimicin 
• 156162-01-5 asimin 
• 507480-62-8 Toluene-4-sulfonic acid (E)-(1S,4R,5R,8S,9R)-4,5-bis-(tert-butyl-dimethyl-silanyloxy)-8-hydroxy-9-methoxymethoxy-1-((R)-1-methoxymethoxy-undecyl)-hexadec-10-en-15-ynyl ester 
• 507480-63-9 C₅₇H₉₈O₁₂S₂Si₂ 
• 507480-66-2 Toluene-4-sulfonic acid (E)-(1S,4R,5R,8S,9R,14S)-4,5-bis-(tert-butyl-dimethyl-silanyloxy)-14-(tert-butyl-diphenyl-silanyloxy)-8-hydroxy-9-methoxymethoxy-1-((R)-1-methoxymethoxy-undecyl)-hexadec-10-en-15-ynyl ester 
• 507480-67-3 (E,11R,12S,15R,16R,19S,20R)-15,16-di(tert-butyldimethylsilyloxy)-25-(tert-butyldiphenylsilyloxy)-11,20-di(methoxymethoxy)-12,19-di(p-toluenesulfonoxy)-21-heptacosen-26-yne 
• 247200-10-8 C₆₂H₁₀₄O₁₃S₂Si₂ 
• 247200-09-5 Toluene-4-sulfonic acid (E)-(1S,4R,5R,8S,9R)-14-benzyloxy-4,5-bis-(tert-butyl-dimethyl-silanyloxy)-8-hydroxy-9-methoxymethoxy-1-((R)-1-methoxymethoxy-undecyl)-tetradec-10-enyl ester 
• 247200-11-9 (2R,5R,2'R,5'R)-5-((E)-(R)-6-Benzyloxy-1-methoxymethoxy-hex-2-enyl)-5'-((R)-1-methoxymethoxy-undecyl)-octahydro-[2,2']bifuranyl 
• 247200-07-3 Toluene-4-sulfonic acid (1S,2R)-1-[(3R,4R)-3,4-bis-(tert-butyl-dimethyl-silanyloxy)-7-oxo-heptyl]-2-methoxymethoxy-dodecyl ester 

Relevant academic research and scientific papers

A modular synthesis of annonaceous acetogenins

A synthesis of four Annonaceous acetogenins, asiminocin, asimicin, asimin, and bullanin, by a modular approach from seven fundamental subunits, A-G, is described. The approach employs a central core aldehyde segment, C, to which are appended an aliphatic terminus, A or B, a spacer subunit, D or E, and a butenolide terminus, F or G. Coupling of the A, B, D, and E segments to the core aldehyde unit is effected by highly diastereoselective additions of enantiopure allylic indium or tin reagents. The butenolide termini are attached to the ACD, BCE, or BCD intermediates by means of a Sonogashira coupling. The design of the core, spacer, and termini subunits is such that any of the C30, C10, or C4 natural acetogenins or stereoisomers thereof could be prepared. IC50 values for the four aforementioned acetogenins against H-116 human colon cancer cells were found to be in the 10-3 to 10-4 μM range. The IC90 activities were ca. 10-3 μM for asimicin and asimin but only 0.1-1 μM for bullanin and asiminocin.

Total synthesis of the cytotoxic threo, trans, threo, trans, threo annonaceous acetogenin asimin and its C-10 epimer: Unambiguous confirmation of absolute stereochemistry

A convergent synthesis of asimin (1) and its C-10 epimer 33 is reported. The essential features of this synthesis include (a) the addition of an enantioenriched γ-OMOM allylic indium reagent to a core C-23 aldehyde precursor to install the C-24-C-34 segment with concomitant introduction of the C-24 and C-23 stereocenters; (b) the addition of an enantioenriched γ- OMOM allylic indium reagent to a core C-16 aldehyde to install the C-10-C-15 segment with formation of the C-15 and C-16 stereocenters, (c) the addition of a dialkyl zinc reagent, catalyzed by a Chiral triflamide-Ti(O-i-Pr)4 complex, to introduce the C-1-C-9 segment with creation of either the 10(R) or 10(S) stereocenters; and (d) aldol condensation of the foregoing C-1-C-34 segment with OTBS-protected lactic aldehyde to incorporate the C-35-C-37 butenolide segment. Removal of the three MOM protecting groups was achieved with aqueous HCl in THF. The 10(R) diastereomer was found to correspond to natural asimin.