A stereoselective synthesis of 3-substituted (S)-pyroglutamic and glutamic acids via OBO ester derivatives
作者:Claus Herdeis、Bernd Kelm
DOI:10.1016/s0040-4020(02)01490-4
日期:2003.1
transformed to the Cbz-protected 4-methyl-2,6,7-trioxabicyclo[2.2.2] octane (OBO) ester. This ortho ester functionality is employed as a bulky steering group for stereoselective introduction of alkyl and aryl groups via 1,4-cuprate addition to 3,4-unsaturated pyroglutamates. After deprotection and ringopening, 3-substituted glutamic acids are obtained.
(S)-焦谷氨酸转化为Cbz保护的4-甲基-2,6,7-三氧杂双环[2.2.2]辛烷(OBO)酯。该原酸酯官能团被用作庞大的导向基团,用于通过向3,4-不饱和焦谷氨酸酯中添加1,4-杯酸酯来立体选择性地引入烷基和芳基。脱保护和开环后,获得3-取代的谷氨酸。