This invention relates to novel compounds having the structural formula I below: and their pharmaceutically acceptable salts, tautomers or in vivo-hydrolysable precursors, compositions and methods of use thereof, wherein R1, R2, Rsu
-
Page/Page column 70
(2009/01/24)
Synthesis of Stereoisomeric 3-Substituted Cyclobutanecarboxylic Acid Derivatives
The preparation of 3-substituted cyclobutanecarboxylic acids by ring forming malonic ester cycloalkylation/saponification/decarboxylation leads to 50:50 cis/trans mixtures.Only some polar ester derivatives 2 can be separated by chromatographic methods.Catalytic hydrogenation of 3-substituted cyclobutanecarboxylic acids 3, however, gives the cis acids 4 with 90-95 percent selectivity.Reduction of the same acids 3 by Zn in aqueous HCl/THF leads to the trans acids 6 with 90-93 percent selectivity.
Dehmlow, Eckehard V.,Schmidt, Stefan
p. 411 - 414
(2007/10/02)
More Articles about upstream products of 87863-08-9