Preparation of 2,2-disubstituted 3-chloropropionic esters
申请人:BASF Aktiengesellschaft
公开号:US04837357A1
公开(公告)日:1989-06-06
2,2-Disubstituted 3-chloropropionic esters I ##STR1## where R.sup.1 and R.sup.2 are each C.sub.1 -C.sub.6 -alkyl, C.sub.2 -C.sub.6 -oxaalkyl, C.sub.2 -C.sub.6 -alkenyl, C.sub.2 -C.sub.6 -oxaalkenyl, aryl or C.sub.7 -C.sub.12 -aralkyl or R.sup.1 -C-R.sup.2 is 5-, 6- or 7-membered ring, R.sup.3 is C.sub.2 -C.sub.6 -oxaalkyl, C.sub.2 -C.sub.6 -alkenyl, C.sub.2 -C.sub.6 -oxaalkenyl or C.sub.7 -C.sub.12 -aralkyl, are prepared by converting 2,2-disubstituted 3-hydroxypropanals II ##STR2## into the esterdiol III ##STR3## reacting this esterdiol III in the presence of a transesterification catalyst with an alcohol R.sup.3 OH to give the 3-hydroxyester IV ##STR4## reacting the hydroxyester IV with a stoichiometric or greater than stoichiometric amount of the thionyl chloride and thermally decomposing the product to give the chloropropionic ester I.
The favorskii rearrangement of dichlorinated methylketones
作者:N. Schamp、N. De Kimpe、W. Coppens
DOI:10.1016/0040-4020(75)80198-0
日期:1975.1
Twenty-two dichlorinated methylketones have been submitted to Favorskiirearrangement in NaOMeMeOH. Distribution of products is strongly dependent on substitution. Primary dichloromethyl-ketones (R2 = H) gave rise to Favorskii esters only. Results are explained by a cyclopropanone intermediate, which is formed stereospecifically by disrotative closure of a delocalized zwitter-ion. Opening of the cyclopropanone