Electrophilic cyclization of amino ketals 14a and 14b with 6 M HCl at 23 degrees C, followed by oxidation with air in 6 M HCl at 100 degrees C, gave tetrahydrophenanthridines 16a and 16b, respectively, which were transformed into the pyrrolophenanthridinium salts 1a and 1b. Compound 1b was shown to be the correct structure of the Narcissus pallidulus constituent, roserine.
A General Method for the Formation of Zinc Enolate Equivalents from Iodoacetates by Diisopropylzinc-Iodine Exchange Reaction: Preparation of<b><i>β</i></b>-Hydroxy Esters
作者:Itaru Sato、Yoshiko Takizawa、Kenso Soai
DOI:10.1246/bcsj.73.2825
日期:2000.12
Diisopropylzinc is found to be a highly efficient reagent for the formation of zinc enolate equivalents from various iodoacetates via iodine-zinc exchange reaction at roomtemperature, affording β-hydroxy esters in highyields by the reaction with aldehydes and ketones.