Stereospecific construction of stereogenic vicinal quaternary carbon atoms. Enantiospecific synthesis of (+)-valerane
作者:Adusumilli Srikrishna、Ranganathan Viswajanani
DOI:10.1016/0040-4039(96)00407-8
日期:1996.4
Stereo- and enantiospecificsynthesis of (+)-valerane starting from R-carvone utilising orthoester Claisen rearrangement and intramolecular diazo ketone cyclopropanation reactions for the construction of the two vicinalquaternarycarbonatoms is described.
Two enantiospecific routes to (+)-valerane starting from (R)-carvone, using a combination of Claisen rearrangement and intramolecular diazo ketone cyclopropanation reactions for the stereoselective generation of the vicinalstereogenicquaternarycarbonatoms, are described. Thus, orthoester Claisen rearrangement of 3-methylcarveol 6 furnishes the ester 9 containing the first quaternarycarbon atom