99727-96-5Relevant academic research and scientific papers
Design, synthesis and cytotoxicity of 7-deoxy aryl discodermolide analogues
Burlingame, Mark A.,Shaw, Simon J.,Sundermann, Kurt F.,Zhang, Dan,Petryka, Joseph,Mendoza, Esteban,Liu, Fenghua,Myles, David C.,LaMarche, Matthew J.,Hirose, Tomoyasu,Freeze, B. Scott,Smith III, Amos B.
, p. 2335 - 2338 (2007/10/03)
A series of 7-deoxy discodermolide analogues in which the lactone fragment 'C' was replaced by aryl substituents were designed, synthesized, and evaluated for cytotoxicity.
Cope Rearrangement in the Thiophene Series
MacDowell, Denis W. H.,Purpura, Joseph M.
, p. 183 - 188 (2007/10/02)
The inability to observe Cope rearrangement at elevated temperature for diethyl α-allylphenylmalonate does not extend to the analogous systems resulting from replacement of the benzene ring by 2- and 3-thiophene nuclei.Thermal rearrangement of diethyl α-allyl-2-thienylmalonate (5) at 250-260 deg C for 12 h produces the expected Cope rearrangement product diethyl (3-allyl-2-thienyl)malonate (6) (49percent) accompanied by ethyl 6-carboethoxy-5,6-dihydro-4H-5-cyclopentathiopheneacetate (7) (28percent).The structural verification of 6 was obtained by degradation to 3-allyl-2-methylthiophene which was compared with an authentic sample obtained by synthesis.The structure of 7 was based on analogy.Similar results were observed with the 3-substituted analogues of 5, both diethyl (2-allyl-3-thienyl)malonate (14) and ethyl 4-carboethoxy-5,6-dihydro-4H-5-cyclopentathiopheneacetate (15) being formed.In this case the structure of 14 was verified by synthesis.Speculative mechanistic considerations are offered regarding the mode of transformation of 6 to 7 and 14 to 15.That the methine proton of the malonate substituent in 6 and 14 is involved in this transformation is seen by the inability of the appropriate methyl-substituted derivative of 6 to undergo thermal cyclization.
