147220-48-2Relevant academic research and scientific papers
Synthesis of solandelactone F, constanolactone A and an advanced intermediate towards solandelactone e from a common synthetic intermediate
Yalla, Raju,Raghavan, Sadagopan
, p. 4572 - 4592 (2019/05/16)
The stereoselective synthesis of solandelactone F, constanolactone A and an advanced intermediate towards solandelactone E, from a common synthetic intermediate, is disclosed. The propargylic sulfide stereocenter is created stereoselectively via carbon-carbon bond formation in the reaction of α-chloro sulfides with alkynylzinc reagents via 1,2-asymmetric induction by a β-siloxy group. The characteristic 1,4-diol motif of the natural products is introduced by a [2,3] sigmatropic rearrangement of an allylic sulfoxide or by the Mislow-Evans-Braverman rearrangement of a propargylic sulfoxide followed by stereoselective reduction of the ensuing α,β-unsaturated ketone. Unlike earlier reports, the C11/C9 carbinol center is created with excellent stereocontrol and derivatives of natural products differing at C14/C12 can be readily obtained. Catalytic asymmetric protocols and substrate-controlled asymmetric induction are utilized for the efficient introduction of the stereogenic centers.
Divergent reactivity via cobalt catalysis: An epoxide olefination
Jamieson, Megan L.,Hume, Paul A.,Furkert, Daniel P.,Brimble, Margaret A.
supporting information, p. 468 - 471 (2016/02/18)
Cobalt salts exert an unexpected and profound influence on the reactivity of epoxides with dimethylsulfoxonium methylide. In the presence of a cobalt catalyst, conditions for epoxide to an oxetane ring expansion instead deliver homoallylic alcohol products, corresponding to a two-carbon epoxide homologation/ring-opening tandem process. The observed reactivity change appears to be specifically due to cobalt salts and is broadly applicable to a variety of epoxides, retaining the initial stereochemistry. This transformation also provides operationally simple access to enantiopure homoallylic alcohols from chiral epoxides without use of organometallic reagents. Tandem epoxidation-homologation of aldehydes in a single step is also demonstrated.
Total synthesis of (-)-zampanolide and structure-activity relationship studies on (-)-dactylolide derivatives
Zurwerra, Didier,Glaus, Florian,Betschart, Leo,Schuster, Julia,Gertsch, Jürg,Ganci, Walter,Altmann, Karl-Heinz
supporting information, p. 16868 - 16883 (2013/03/14)
A new total synthesis of the marine macrolide (-)-zampanolide (1) and the structurally and stereochemically related non-natural levorotatory enantiomer of (+)-dactylolide (2), that is, ent-2, has been developed. The synthesis features a high-yielding, selective intramolecular Horner-Wadsworth-Emmons (HWE) reaction to close the 20-membered macrolactone ring of 1 and ent-2. The β-keto phosphonate/aldehyde precursor for the ring-closure reaction was obtained by esterification of a ω-diethylphosphono carboxylic acid fragment and a secondary alcohol fragment incorporating the THP ring that is embedded in the macrocyclic core structure of 1 and ent-2. THP ring formation was accomplished through a segment coupling Prins-type cyclization. Employing the same overall strategy, 13-desmethylene-ent-2 as well as the monocyclic desTHP derivatives of 1 and ent-2 were prepared. Synthetic 1 inhibited human cancer cell growth in vitro with nM IC50 values, while ent-2, which lacks the diene-containing hemiaminal-linked side chain of 1, is 25- to 260-fold less active. 13-Desmethylene-ent-2 as well as the reduced versions of ent-2 and 13-desmethylene-ent-2 all showed similar cellular activity as ent-2 itself. The same activity level was attained by the monocyclic desTHP derivative of 1. Oxidation of the aldehyde functionality of ent-2 gave a carboxylic acid that was converted into the corresponding N-hexyl amide. The latter showed only μM antiproliferative activity, thus being several hundred-fold less potent than 1. It's the side chain that matters: The marine macrolide (-)-zampanolide (1) has been synthesized via (-)-dactylolide (ent-2), the non-natural enantiomer of the marine natural product (+)-dactylolide (2), employing a high-yielding intramolecular Horner-Wadsworth-Emmons reaction to close the macrolactone ring. While the hemiaminal-linked side chain in 1 is crucial for nanomolar antiproliferative activity, the methylene group and the aldehyde functionality in ent-2 are dispensable. A monocyclic destetrahydropyran derivative of 1 shows equal activity as ent-2. Copyright
A concise stereoselective formal total synthesis of the cytotoxic macrolide (+)-Neopeltolide via Prins cyclization
Yadav, Jhillu Singh,Krishana, Gunda Gopala,Kumar, Satya Narayana
body text, p. 480 - 487 (2010/03/03)
A convergent and highly stereoselective formal total synthesis of the naturally occurring, cytotoxic 14-membered macrolide neopeltolide has been achieved via two Prins cyclizations.
Synthesis of (-)-dactylolide and 13-desmethylene-(-)-dactylolide and their effects on tubulin
Zurwerra, Didier,Gertsch, Juerg,Altmann, Karl-Heinz
supporting information; experimental part, p. 2302 - 2305 (2010/08/05)
An efficient new synthesis has been elaborated for non-natural (-)-dactylolide ((-)-2) and its 13-desmethylene analogue 4, employing a HWE-based macrocyclization approach with β-keto-phosphonate/aldehyde 19 and the respective 13-desmethylene derivative as the key intermediates. Both (-)-2 and 4 as well as the corresponding C20 alcohols inhibit human cancer cell proliferation with IC50 values in the sub-micromolar range and induce the polymerization of tubulin in vitro.
Total synthesis of decarestrictine i and botryolide B via RCM protocol
Radha Krishna, Palakodety,Rao, T. Jagannadha
scheme or table, p. 3130 - 3132 (2010/08/21)
A convergent stereoselective total synthesis of decarestrictine I (1) and botryolide B (1a) invoking a common synthetic strategy is reported. The key steps are: ring-closing metathesis of epoxy dienoic esters obtained through the Yamaguchi esterification
A [3 + 3] annelation approach to (+)-rhopaloic acid B
Brioche, Julien C. R.,Goodenough, Katharine M.,Whatrup, David J.,Harrity, Joseph P. A.
, p. 3941 - 3943 (2008/02/11)
A general and enantiospecific [3 + 3] reaction toward functionalized pyrans is reported that has been employed in the first enantioselective synthesis of (+)-rhopaloic acid B.
A stereoselective synthesis of verbalactone-determination of absolute stereochemistry
Sharma,Govardhan Reddy, Ch.
, p. 7483 - 7485 (2007/10/03)
A total synthesis of verbalactone has been achieved starting from l-malic acid. A total synthesis of verbalactone has been achieved starting from l-malic acid. The two appropriately protected acid and alcohol segments were prepared from l-malic acid and l
Investigation into the absolute stereochemistry of the marine sponge alkaloid pyrinodemin A
Romeril, Stuart P.,Lee, Victor,Baldwin, Jack E.,Claridge, Timothy D. W.,Odell, Barbara
, p. 7757 - 7761 (2007/10/03)
The absolute configuration of the marine sponge alkaloid pyrinodemin A is established by organic synthesis.
First total synthesis and determination of the absolute configuration of strictifolione, a new 6-(ω-phenylalkenyl)-5,6-dihydro-α-pyrone, isolated from Cryptocarya strictifolia
Juliawaty, Lia Dewi,Watanabe, Yoshimi,Kitajima, Mariko,Achmad, Sjamsul Arifin,Takayama, Hiromitsu,Aimi, Norio
, p. 8657 - 8660 (2007/10/03)
Starting from (S)-malic acid and (S)-glycidol, the first total synthesis of strictifolione, a new 6-(ω-phenylalkenyl)-5,6-dihydro-α-pyrone isolated from Cryptocarya strictifolia, was accomplished, which confirmed its structure including the absolute confi
