Synthesis of (±)-Smenochromene D (Likonide B) Using a Regioselective Claisen Rearrangement
作者:Christopher Moody、Marjorie Bruder
DOI:10.1055/s-2008-1032090
日期:——
A synthesis of the unusual ansa farnesyl hydroquinone smenochromene D (likonide B) is described, in which the key steps are a regioselective microwave-mediated Claisen rearrangement of an aryl propargyl ether to deliver the chromene ring, and macrocyclisation via an intramolecular Mitsunobu reaction.
Synthesis of (±)-likonide B (smenochromene D) using a regioselective Claisen rearrangement, separation of the enantiomers and stereochemical assignment
作者:Marjorie Bruder、Stephen J. Smith、Alexander J. Blake、Christopher J. Moody
DOI:10.1039/b901358j
日期:——
A synthesis of the unusual ansa-bridged farnesyl hydroquinone derivative likonide B in racemic form is described. The natural product, also known as smenochromene D, was obtained from geranylacetone by a route in which the key steps are a regioselective microwave-mediated Claisen rearrangement of an aryl propargyl ether to deliver the chromene ring, and macrocyclization via an intramolecular Mitsunobu
Enantioselective Cyclopropanation of Allylic Alcohols with Dioxaborolane Ligands: Scope and Synthetic Applications
作者:André B. Charette、Hélène Juteau、Hélène Lebel、Carmela Molinaro
DOI:10.1021/ja982055v
日期:1998.11.1
the conversion of allylicalcohols into the corresponding enantiomerically enriched cyclopropanes using bis(iodomethyl)zinc. A variety of chiral, nonracemic cyclopropylmethanols could be obtained according to this method. This methodology was extended with success to the cyclopropanation of unconjugated and conjugated polyenes and homoallylic alcohols. The cyclopropanation of allylic carbamates has also
The chemo- and enantioselective cyclopropanation of allylic alcohols containing additional olefins was investigated using the dioxaborolane-derived reagent. High chemo- and enantioselectivities were usually observed if a mixture of the chiral dioxaborolane ligand/allylic alcohol was treated with a solution of Zn(CH2I)2·DME complex.
A method for the palladium-catalyzed allylic oxidation of olefins
作者:John E. McMurry、Pavel Kočotovský
DOI:10.1016/s0040-4039(01)81391-5
日期:1984.1
Olefins are converted into allylic acetates by treatment in aceticacid with a catalytic amount of palladium bis(trifluoroacetate) and one equivalent of benzoquinone as oxidant. The reaction is selective for oxidation of a terminal methyl group of geranylacetone.