Regioselective Synthesis of O-Methyl Derivatives of the Trihydroxy Anthraquinones Morindone and Nataloe-Emodin
作者:Donald W. Cameron、D. Ross Coller
DOI:10.1071/ch99106
日期:——
Cycloaddition chemistry of dichloronaphthoquinones has led to regioselective
syntheses of all regioisomeric α-O- methyl
derivatives of morindone (2) and nataloe-emodin (4), including the natural
anthraquinone ethers (1) and (3).
A convergent approach to swinholide A. Stereoselective construction of the C<sub>3</sub>–C<sub>17</sub>fragment of swinholide A
作者:A. P. Patron、P. K. Richter、M. J. Tomaszewski、R. A. Miller、K. C. Nicolaou
DOI:10.1039/c39940001147
日期:——
A strategy for a totalsynthesis of the cytotoxic dimeric macrolide swinholide A (1, Scheme 1) is outlined and a stereoselective construction of the suitably functionalized C3–C17 fragment 4, starting with building blocks 6, 7, 9 and 10 is described.
We have accomplished a 10-step (longest linear) totalsynthesis of nannocystin A on a four hundred milligram scale. The previously reported Kobayashi vinylogousMukaiyamaaldolreaction to connect C4 and C5 was unreproducible during the scaling up process. A more convenient and cost-efficient Keck asymmetric vinylogousaldolreaction was employed to improve this transformation.
Kulokekahilide-2, a Cytotoxic Depsipeptide from a Cephalaspidean Mollusk <i>Philinopsis speciosa</i>
作者:Yoichi Nakao、Wesley Y. Yoshida、Yuuki Takada、Junji Kimura、Liu Yang、Susan L. Mooberry、Paul J. Scheuer
DOI:10.1021/np049949f
日期:2004.8.1
A cytotoxic depsipeptide, kulokekahilide-2 (1), was isolated from a cephalaspidean mollusk, Philinopsis speciosa. The structure elucidation of kulokekahilide-2 was carried out by spectroscopic analysis and chemical degradation. Kulokekahilide-2 showed potent cytotoxicity against several cell lines (P388, SKOV-3, MDA-MB-435, and A-10 with IC50 values ranging from 4.2 to 59.1 nM) indicating cancer cell selectivity.
Enolisation of αβ-unsaturated esters : regio- and geometrical control
作者:Donald W. Cameron、Mark G. Looney、Judy A. Pattermann
DOI:10.1016/0040-4039(95)01531-0
日期:1995.10
LDA-Mediated γ-deprotonation of simple αβ-unsaturatedesters occurs (Z)- to the ester group; silylation then leads to oxy butadienes with strong regio- and geometrical selectivity.