A novel approach towards the synthesis of functionalized taxane skeleton employing wittig rearrangement
作者:J.S. Yadav、Renduchintala Ravishankar
DOI:10.1016/s0040-4039(00)78803-4
日期:1991.6
An expeditious synthesis of Taxol skeleton is described utilizing the combination of intramolecular Diels-Alder (IMDA) and Wittig rearrangement reactions.
Bridgehead dienes. Thermal generation of the bicyclo[3.3.1]nona-1(2),4(5)-diene (ZZ) ring system
作者:K.J. Shea、L.D. Burke
DOI:10.1016/s0040-4039(01)80975-8
日期:1987.1
The bicyclo[3.3.1]nona-1(1),4(5)-diene (ZZ) ring system has been generated by intramolecular Diels-Alder cycloaddition of methyl 7-methylene-non-2-yn-8-enoate. This highly strained bridgehead diene undergoes a homo 1,5-hydrogen shift to yield a [3.3.1] propellane product.
to produce unisolable allylchromium species which add efficiently to aldehydes or ketones with high degree of stereo- and chemoselectivity. Particularly, high threo selectivity is observed in the reaction of aldehydes and 1-bromo-2-butene and is ascribed to a chair-like six-membered transition state. Simple reduction of allylic and benzylic halides produces biallyls and bibenzyls, while gem-dibromocyclopropanes
organozinc derivatives to Iron stabilized TMM-alcohols. These are decomplexed, under partial hydrogenation, by photolysis in acetic acid to give allylic and homoallylic isoprenoic alcohols. Starting from the optically active complex (+)-3, this allows a rapid synthesis of (R)-(-)-Ipsdienol of high ee.
Arthropodicidal pyrazolines, pyrazolidines and hydrazines
申请人:E. I. Du Pont de Nemours and Company
公开号:US05474998A1
公开(公告)日:1995-12-12
Arthropodicidal pyrazoline, pyrazolidine and hydrazine compounds, including all their geometric and stereoisomers, agriculturally suitable salts thereof and compositions containing them; and a method for controlling arthropods employing said compounds which are: ##STR1## wherein Q, X, X.sup.1, Y and G are as defined in the text.