Synthesis of a Lactone Diastereomer of the Cembranolide Uprolide D
作者:James A. Marshall、Céline A. Griot、Harry R. Chobanian、William H. Myers
DOI:10.1021/ol101776e
日期:2010.10.1
A convergent stereoselective synthesis of a C1/C14 bis-epimer of uprolide D is described in which an intramolecular Barbier-type reaction was employed for macrocyclization with concomitant introduction of the C1 and C14 stereocenters of a fused α-methylene lactone ring through an anti-Felkin−Anh transition state. Unlike previous examples of allyl chromium additions, none of the Felkin−Anh derived adduct
Synthesis of Enantiomerically Pure 3-Amino-2-methylenealkanoates (Aza-Morita-Baylis-Hillman Adducts) Mediated by Cinchona Alkaloids
作者:Gianluca Martelli、Mario Orena、Samuele Rinaldi
DOI:10.1002/ejoc.201101244
日期:2011.12
reacted with (S)-1-(4-methoxyphenyl)ethylamine in the presence of astoichiometric amount of quinidine to yield (R)-3-[(tert-butoxycarbonyl)amino]-2-methylenealkanoates (aza-Morita–Baylis–Hillmanadducts) in enantiomericallypure form.
Further Synthetic and Biological Studies on Vitamin D Hormone Antagonists Based on C24-Alkylation and C2α-Functionalization of 25-Dehydro-1α-hydroxyvitamin D<sub>3</sub>-26,23-lactones
on process, and the 23,24-trans lactone derivatives were derived from these via inversion of the C23 stereochemistry. The biological evaluation revealed that both binding affinity for chick vitamin D hormone receptor and antagonistic activity (inhibition of vitamin D hormone induced HL-60 cell differentiation) were affected by the orientation and chain-length of the primary alkyl group on the lactone