188926-22-9

Upstream product

• 104713-30-6 (S)-methyl 5-(benzyloxy)-3-hydroxypentanoate 
• 74-88-4 methyl iodide 
• 99017-80-8 methyl 5-benzyloxy-3-oxopentanoate 

Downstream Products

• 162600-54-6 cryptophycin-24 
• 219606-86-7 tert-butyl (5S,6R)-5-[(2S)-2-[3-[(2R)-2-tert-butoxycarbonylamino-3-(4-methoxyphenyl)-propionylamino]propionyloxy]-4-methylpentanoyloxy]-6-methyl-8-phenylocta-2(E),7(E)-dienoate 
• 219606-79-8 tert-butyl (2E,5S,6R,7E)-5-{[tert-butyl(dimethyl)silyl]oxy}-6-methyl-8-phenylocta-2,7-dienoate 
• 188926-26-3 {(1E,3R,4S)-4,6-bis{[(tert-butyl)dimethylsilyl]oxy}-3-methylhex-1-enyl}benzene 
• 208581-50-4 (3S,4R,5E)-3-{[tert-butyl(dimethyl)silyl]oxy}-4-methyl-6-phenylhex-5-en-1-ol 
• 178977-57-6 tert-butyl (5S,6R,2E,7E)-5-hydroxy-6-methyl-8-phenyl-2,7-octadienoate 
• 162465-28-3 (5S)-<<(1,1-dimethylethyl)dimethylsilyl>oxy>-(6R)-methyl-8-phenyl-(2E,7E)-octadienoic acid methyl ester 
• 162465-27-2 (3S,4R,5E)-3-[(tert-butyldimethylsilyl)oxy]-4-methyl-6-phenyl-5-hexenal 
• 162473-78-1 desepoxyarenastatin A 

Relevant academic research and scientific papers

Formal syntheses of cryptophycin A and arenastatin A

Efficient formal syntheses of the tubulin binding antitumor agents cryptophycin A (1) and arenastatin A (2) are detailed. The readily available β-keto ester 4 was subjected to catalytic asymmetric hydrogenation, Frater alkylation, and selective functional

Total synthesis of cryptophycin-24 (arenastatin A) amenable to structural modifications in the C16 side chain

Two efficient protocols for the synthesis of tert-butyl (5S,6R,2E,7E)-5-[(tert-butyldimethylsilyl)-oxy]-6-methyl-8-phenyl-2,7-octadie noate, a major component of the cryptophycins, are reported. The first utilized the Noyori reduction and Frater alkylation of methyl 5-benzyloxy-3-oxopentanoate to set two stereogenic centers, which became the C16 hydroxyl and C1' methyl of the cryptophycins. The second approach started from 3-p-methoxybenzyloxypropanal and a crotyl borane reagent derived from (-)-α-pinene to set both stereocenters in a single step and provided the dephenyl analogue, tert-butyl (5S,6R,2E)-5-[(tert-butyldimethylsilyl)oxy]-6-methyl-2,7-octadienoate, in five steps. This compound was readily converted to the 8-phenyl compound via Heck coupling. The silanyloxy esters were efficiently deprotected and coupled to the C2-C10 amino acid fragment to provide desepoxyarenastatin A and its dephenyl analogue. The terminal olefin of the latter was further elaborated via Heck coupling. Epoxidation provided cryptophycin-24 (arenastatin A).