Synthesis of enantiomerically pure (S)-3-trichloromethylbutyric acid via asymmetric conjugate addition of trichloromethyl metal compounds to a chiral enoate. Activation effect of a sulfonylamino group
作者:Günter Helmchen、Günter Wegner
DOI:10.1016/s0040-4039(00)95121-9
日期:1985.1
(+)(S)-3-Trichloromethylbutyric acid, a building block for syntheses of various marine natural products, can be prepared via 99:1 stereoselective conjugate addition of Cl3CMgCl to the crotonate of a chiral auxiliary containing a sulfonylamino substituent.
The relative and absolute configuration of dysidenin has been determined by chemical correlation between dysidenin, isodysidenin and their respective dechlorinated derivatives.
Synthetic Studies of Trichloroleucine Marine Natural Products. Michael Addition of LiCCl<sub>3</sub> to <i>N</i>-Crotonylcamphor Sultam
作者:Sarah E. Brantley、Tadeusz F. Molinski
DOI:10.1021/ol991256g
日期:1999.12.1
Conjugate addition of trichloromethyllithium to N-crotonylcamphorsultam occurs in good yield at -98 degrees C in THF-hexanes, The formal incorporation of the "CCl3-" anion by 1,4-addition allows subsequent transformation to useful trichloromethyl-substituted intermediates.
Total synthesis of (+)-demethyldysidenin and (-)-demethylisodysidenin, hexachlorinated amino acids from the marine sponge Dysidea herbacea. Assignment of absolute stereochemistry