Traceless Stereoinduction in the One-Pot Assembly of All Three Rings of Hexahydrodibenzopyrans
作者:Keith A. Korthals、William D. Wulff
DOI:10.1021/ja077579m
日期:2008.3.1
stereochemical information from the chiral center at the propargylic ether in the alkyne to the planar center of chirality in the in situ generated arene chromium tricarbonyl complexed intermediate and finally, after base-induced elimination to generate an o-quinone methide chromium tricarbonyl complexed intermediate, a transfer of chiralityfrom the planar center of chirality in the o-quinone methide
Several (1–6) 9-anthraceneacrylic esters were synthesized in order to study photochemical E(trans)–Z(cis) isomerization. All of the compounds 1–6 underwent selective E-to-Z isomerization upon direct excitation (> 400 nm) in organic solvents, leading to the formation of a thermodynamically less stable Z isomer over 96%. Triplet sensitized isomerization selectively produces the Z-to-E isomer in over
Synthesis of (R,S)-10-methyloctadecanoic acid (tuberculostearic acid) and key chiral 2-methyl branched intermediates
作者:Paul A. Wallace、David E. Minnikin、Katharine McCrudden、Andrea Pizzarello
DOI:10.1016/0009-3084(94)90067-1
日期:1994.5
Tuberculostearicacid, (R)-10-methyloctadecanoic acid, is a characteristic component of pathogenic mycobacteria and related organisms. Sensitive detection of this acid in infected material allows rapid detection of mycobacterial disease. A novel, convergent synthesis of tuberculostearicacid and key chiral intermediates is described in this communication, to provide a reference compound. Racemic and
Several primary and secondary symmetrical diols, ranging from propane-1,3-diol to decane-1,10-diol, are selectively monoprotected by monotetrahydropyranyl ether formation catalysed by a strongly acidic ion-exchange resin (Dowex 50w × 2, 50–100 mesh) in a 3,4-dihydro-2H-pyran-hydrocarbon mixture.
Chemoselective tetrahydropyranylation of alcohols and phenols using polystyrene supported aluminium chloride as a catalyst
作者:Bahman Tamami、Kaveh Parvanak Borujeny
DOI:10.1016/j.tetlet.2003.11.056
日期:2004.1
A simple, efficient and highly chemoselective method for tetrahydropyranylation of alcohols and phenols has been developed by their reaction with 3,4-dihydro-2H-pyran at room temperature in the presence of a catalytic amount of polystyrenesupported AlCl3. The method is also highly selective for monoprotection of symmetrical diols.