208581-50-4Relevant academic research and scientific papers
Total synthesis of cryptophycin 3
Danner, Paulami,Bauer, Matthias,Phukan, Prodeep,Maier, Martin E.
, p. 317 - 325 (2007/10/03)
The depsipeptide cryptophycin 3 (5) and the cryptophycin analogue 43 were prepared from the corresponding four subunits, The tripeptide analogue 34 was acquired from the starting amino ester 33, which contains fragments D and C. After extension at the car
Flexible routes to the 5-hydroxy acid fragment of the cryptophycins
Phukan, Prodeep,Sasmal, Sanjita,Maier, Martin E.
, p. 1733 - 1740 (2007/10/03)
Two solutions to establishing the anti stereochemistry of the vicinal stereocenters in the 5-hydroxy acid subunit of cryptophycin, based on initial Evans syn aldol reactions between an N-(propionyl)oxazolidinone 4 and a C3 aldehyde, were developed. In the first route, the secondary hydroxy group was inverted by use of Mitsunobu reaction conditions, whereas the second route features an inversion of the methyl-bearing stereocenter, achieved by reductive removal of the chiral auxiliary, elimination to afford the terminal alkene, and anti-selective hydroboration. The aryl part can be attached either by Wittig-Horner olefination or by a modified Julia coupling. Both routes provide the hydroxy acid 16 in a very efficient manner. The substrate for the hydroboration, alkene 22, could also be obtained from (S)-malic acid. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Total synthesis of cryptophycin-24 (arenastatin A) amenable to structural modifications in the C16 side chain
Eggen,Mossman,Buck,Nair,Bhat,Ali,Reiff,Boge,Georg
, p. 7792 - 7799 (2007/10/03)
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).
Total Synthesis of Cryptophycins-1, -3, -4, -24 (Arenastatin A), and -29, Cytotoxic Depsipeptides from Cyanobacteria of the Nostocaceae
White, James D.,Hong, Jian,Robarge, Lonnie A.
, p. 6206 - 6216 (2007/10/03)
A convergent synthesis of cryptophycins has been developed in which (5S,6R)-5-hydroxy-6-methyl-8-phenylocta-2(E),7(E)-dienoic acid (A) is coupled with an amino acid segment (B). Two stereo-selective routes to A are described, the first employing allylatio
A short enantioselective synthesis of a component of cryptophycin A and arenastatin A
Furuyama, Masaaki,Shimizu, Isao
, p. 1351 - 1357 (2007/10/03)
Synthesis of 1, a component of cryptophycin A 2 and arenastatin A 3, was achieved by applying palladium-catalyzed reductive ring opening of optically active alkenyl oxirane 13 for the construction of the vicinal stereogenic centers.
A concise synthesis of the cytotoxic depsipeptide arenastatin A
White, James D.,Hong, Jian,Robarge, Lonnie A.
, p. 8779 - 8782 (2007/10/03)
Arenastatin A (1, cryptophycin 24) was synthesized by convergence of hydroxy ester 16 with amino acid derivative 27; two independent and highly efficient routes to 16 are disclosed.
Formal syntheses of cryptophycin A and arenastatin A
Ali, Syed M.,Georg, Gunda I.
, p. 1703 - 1706 (2007/10/03)
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
