Synthesis of .alpha.-halocinnamate esters via solvolytic rearrangement of trichloroallyl alcohols
摘要:
Aryl trichlorovinyl ketones undergo regioselective reduction to the corresponding carbinols with sodium borohydride in alcoholic solvents and are transformed to the (Z)-alpha-chlorocinnamate ester derivatives via an acid-catalyzed allylic rearrangement. Michael addition of ammonia to these ester derivatives affords cis- and/or trans-aziridine amides. The facile rearrangement allows the synthesis of d,l-phenylalanine derived from perchloroethylene and toluene.
Synthesis of .alpha.-halocinnamate esters via solvolytic rearrangement of trichloroallyl alcohols
摘要:
Aryl trichlorovinyl ketones undergo regioselective reduction to the corresponding carbinols with sodium borohydride in alcoholic solvents and are transformed to the (Z)-alpha-chlorocinnamate ester derivatives via an acid-catalyzed allylic rearrangement. Michael addition of ammonia to these ester derivatives affords cis- and/or trans-aziridine amides. The facile rearrangement allows the synthesis of d,l-phenylalanine derived from perchloroethylene and toluene.
Reactions of α,β-Unsaturated Carboxylates, Malonates and Phenylacetates with Manganese(III) Acetate in the Presence of Chloride Ions
作者:Hiroshi Yonemura、Hiroshi Nishino、Kazu Kurosawa
DOI:10.1246/bcsj.60.809
日期:1987.2
The reaction of alkyl (E)-3-phenylpropenoates with manganese(III) acetate in the presence of Cl− ions gave alkyl (Z)-2-chloro-3-phenylpropenoates and alkyl 2,3-dichloro-3-phenylpropanoates. Ethyl (E)-2,3-diphenylpropenoate yielded ethyl 2,3-dichloro-2,3-diphenylpropanoate. Alkyl 3,3-diphenylpropenoates gave mainly alkyl 2-chloro-3,3-diphenyl-propenoates. Ethyl 1-cyclohexenecarboxylate gave ethyl 1
Finely-tuned ruthenium-catalyzed highly chemoselective and enantioselectivehydrogenation of gamma-halo-gamma,delta-unsaturated-beta-keto esters at the carbonyl group was achieved under neutral reaction conditions (ee up to 97%). Both olefin and alkenyl halogen moieties, which are labile underhydrogenationconditions, remained untouched during the reaction.