(-)-Cryptaustoline: its synthesis, revision of absolute stereochemistry, and mechanism of inversion of stereochemistry
作者:A. I. Meyers、Thais M. Sielecki、Debbie C. Crans、Robert W. Marshman、Thanh H. Nguyen
DOI:10.1021/ja00048a020
日期:1992.10
The asymmetric synthesis of (S)-(+)-cryptaustoline was accomplished and found to differ in sign of rotation with the natural «S»-(-)-material. The previously assigned absolute configuration was found to be incorrect and is now corrected. The reversal in stereochemistry came about through an unusual manner involving (S)-(+)-laudanosoline (3) cyclizing to (R)-(-)-cryptaustoline ((-)-1c). The mechanism
Recent progress using chiral formamidines in asymmetric syntheses
作者:A.I. Meyers
DOI:10.1016/s0040-4020(01)88523-9
日期:1992.3
The ability to generate a carbanion next to nitrogen in a chiral environment has led to a number of useful asymmetric routes to alkaloids and related substances. Mechanistic studies have been conducted to understand the nature of these alkylations.