36650-62-1Relevant articles and documents
Megastigmane, benzyl and phenethyl alcohol glycosides, and 4,4'- dimethoxy-β-truxinic acid catalpol diester from the leaves of Premna subscandens Merr.
Sudo, Hirokazu,Ide, Toshinori,Otsuka, Hideaki,Hirata, Eiji,Takushi, Anki,Shinzato, Takakazu,Takeda, Yoshio
, p. 542 - 546 (2000)
Extensive isolation work on the n-BuOH-soluble fraction obtained from the leaves of Premna subscandens, collected on Ishigaki island, Okinawa, afforded six compounds. Two were identified as megastigmane glucosides, 7- (3,5-dihydroxy-1,1,5-trimethylcyclohexylidene)-9-methylprop-8-enyl 9-O-β-D- glucopyranoside and 3-hydroxy-5,6-epoxy-β-ionol 9-O-β-D-glucopyranoside. The structures of the remaining four new compounds were elucidated to be a 2'-O-β-D-apiofuranosyl derivative of 3-hydroxy-5,6-epoxy-β-ionol 9-O-β-D- glucopyranoside, named premnaionoside, benzyl alcohol β-D-(2'-O-β-D- xylopyranosyl)glucopyranoside, phenethyl alcohol β-D-(2'-O-β-D- glucopyranosyl)glucopyranoside, and 4,4'-dimethoxy-β-truxinic acid catalpol diester by spectroscopic analyses.
Construction of Cyclobutanes by Multicomponent Cascade Reactions in Homogeneous Solution through Visible-Light Catalysis
Lei, Tao,Zhou, Chao,Wei, Xiang-Zhu,Yang, Bing,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
supporting information, p. 879 - 884 (2019/01/04)
[2+2] Photocycloaddition of two olefins is a general method to assemble the core scaffold, cyclobutane, found in numerous bioactive molecules. A new approach to synthesize cyclobutanes through multicomponent cascade reactions by merging aldol reaction and Witting reaction with visible-light-induced [2+2] cycloaddition is reported. An array of cyclobutanes with high selectivity has been achieved from commercially available aldehydes, ketones (or phosphorus ylide), and olefins with visible-light irradiation of a catalytic amount of (fac-tris(2-phenylpyridinato-C2,N)iridium) ([Ir(ppy)3]) at room temperature. Control experiments and spectroscopic studies revealed that the triplet–triplet energy transfer from the excited [Ir(ppy)3]* to enones, generated in situ from aldehyde and ketone or aldehyde and phosphorus ylide, is responsible for these simple and efficient muticomponent transformations.
Templating photodimerization of trans-cinnamic acid esters with a water-soluble Pd nanocage
Karthikeyan,Ramamurthy
, p. 452 - 458 (2007/10/03)
A water-soluble octahedral Pd nanocage acting as a reaction vessel templates the photodimerization of substituted trans-cinnamic acid methyl esters in water. Irradiation of the host-guest complexes of trans-cinnamic acid methyl esters with the Pd nanocage resulted in selective formation of a syn head-head dimer in addition to the corresponding cis isomer. These results suggest that the guest molecules are preoriented in a selective fashion with the hydrophilic ester group facing water and the hydrophobic aryl group tucked within the cavity of the host. Such an orientation occurs at the hydrophobic-hydrophilic interface between the nanocage exterior and interior. Weak intermolecular C-H-π and π-π interactions between the host and the guest(s) are likely to be responsible for the lack of mobility of the reactant olefins during their short excited-state lifetime.
