113240-53-2Relevant academic research and scientific papers
Total synthesis of ent-pavettamine
Bode, Moira L.,Fernandes, Manuel A.,Rousseau, Amanda L.,Zimuwandeyi, Memory
supporting information, p. 1440 - 1446 (2021/06/16)
Pavettamine, a plant toxin first isolated from Pavetta harborii in 1995, was previously identified as a polyamine with C2 symmetry and a 1,3-syn-diol moiety on a C10 carbon backbone – one of very few substituted polyamines to be isolated from nature. Its absolute configuration was later established by our first reported total synthesis in 2010. Herein we report the first total synthesis of the enantiomer of pavettamine, ent-pavettamine. The symmetrical structure of the molecule allows for the synthesis of a common C5 fragment that can be divergently transformed into two synthons for later convergent coupling to furnish the target carbon framework. Based on the success of the protocol we employed for the synthesis of the naturally occurring pavettamine, (S)-malic acid was again the starting material of choice for the synthesis of the two individual C5 fragments, with strategic differences in terminal-group manipulation allowing for the synthesis of ent-pavettamine rather than pavettamine. Chain extension and stereoselective ketone reduction were achieved using the (R)-methyl p-tolyl sulfoxide chiral auxiliary to give the desired 1,3-syn-diol C5 unit. A protecting-group strategy was also developed for the orthogonal protection of the alcohol and amine functional groups as they were unveiled. The functionalized C5 fragments were coupled via reductive amination revealing the C10 carbon backbone. Deprotection of the alcohol and amine functional groups successfully provided ent-pavettamine as a TFA salt.
Total synthesis of solandelactones A, B, E, and F exploiting a tandem petasis-claisen lactonization strategy
White, James D.,Lincoln, Christopher M.,Yang, Jongtae,Martin, William H. C.,Chan, David B.
, p. 4139 - 4150 (2008/09/20)
(Chemical Equation Presented) Solandelactones A, B, E, and F were synthesized using Nozaki-Hiyama-Kishi coupling of iododiene 13 with aldehydes 14 and 99 obtained by oxidation of alcohols 92 and 94. Key steps in the synthesis of 92 and 94 were (i) a Nagao asymmetric acetate aldol reaction of aldehyde 77 with thionothiazolidine 78 to set in place an alcohol that becomes the (75) lactone center of solandelactones, (ii) a Simmons-Smith cyclopropanation of 80 directed by this alcohol, and (iii) Petasis methylenation of cyclic carbonate 90 in tandem with a Claisen rearrangement that generates the octenalactone portion of solandelactones. Synthesis of solandelactones A, B, E, and F confirmed their gross structure and absolute configuration at C7, 8, 10, and 14 but showed that alcohol configuration at C11 must be reversed in pairs, A/B and E/F, from the previous assignment made to these hydroid metabolites. Thus, solandelactones A and B are correctly represented by 2 and 1, respectively, whereas solandelactones E and F are 6 and 5. A biogenesis of solandelactones is proposed for these C22 oxylipins that parallels a hypothesis put forward previously to explain the origin of C20 cyclopropane-containing algal products.
Total synthesis of solandelactones E and F, homoeicosanoids from the hydroid Solanderia secunda
White, James D.,Martin, William H.C.,Lincoln, Christopher,Yang, Jongtae
, p. 3481 - 3483 (2008/02/12)
Asymmetrie total syntheses of solandelactones E and F confirmed that hydroxyl configuration at C11 in these oxylipins had been misassigned and that the stereochemistry at this center should be reversed. Key steps in the synthesis involved a Nagao asymmetr
Novel boronate esters
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Page/Page column 11, (2008/06/13)
The present invention relates to optically active boronate derivatives which are useful as intermediates for the synthesis of HMG-CoA enzyme inhibitors such as atorvastatin, cerivastatin, rosuvastatin, pitavastatin, and fluvastatin.
A Highly Stereoselective Route to the Four Stereoisomers of a Six-Carbon Synthon
Prasad, Kapa,Chen, Kau-Ming,Repic, Oljan,Hardtmann, Goetz E.
, p. 307 - 310 (2007/10/02)
The syntheses of chiral synthones 13-16 are described utilizing the chiral pool approach starting from either S- or R-malic acid.
Pyrimidinyl-substituted hydroxyacids, lactones and esters and pharmaceutical compositions containing them
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, (2008/06/13)
Compounds of formula I wherein R1, R2, Q, X and Y have various significances,in free acid form, or in the form of an ester or δ-lactone thereof, or in salt form as appropriate, are described. They are indicated for use as hypolipoproteinemic and anti-athe
Processes for the synthesis of diprotected R[R*,S*]-3,5-dihydroxy-6-oxohexanoate esters
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, (2008/06/13)
Process for the synthesis of compounds of the formula STR1 in R[R*,S*] enantiomeric form, wherein each P1 is independently an hydroxy group-protecting group, and R2z is C1-4 alkyl, benzyl or allyl, comprising, as a key step when R2z is R2x, the reaction of the compound of the formula STR2 in (S) enantiomeric form with a compound of the formula to obtain a compound of the formula STR3 in (S) enantiomeric form, and, as a key step when R2z is R2y, the reaction of a compound of the formula STR4 in (S) enantioimeric form with a compound of the formula to obtain a compound of the formula STR5 in (S) enantiomeric form, wherein R2x is primary or secondary C1-4 alkyl, benzyl or allyl, R2y is C1-4 alkyl not containing an asymmetric carbon atom, and R3 ' is methyl or ethyl, processes for the synthesis of compounds of the formula STR6 comprising reacting a compound of the formula STR7 with the reaction product of a strong base and a compound of the formula STR8 optionally followed by, when R2z is allyl, cleavage of the allyl and P1 groups to obtain the corresponding compound of the formula STR9 wherein each R7 is methyl or ethyl, R is as defined in the specification, and each P1 independently and R2z are as defined above, and the compounds of the formula STR10 wherein R and each R7 are as defined above.
