Total Synthesis of (+)-Alexine by Utilizing a Highly Stereoselective [3+2] Annulation Reaction of anN-Tosyl-α-Amino Aldehyde and a 1,3-Bis(silyl)propene
作者:Martina Dressel、Per Restorp、Peter Somfai
DOI:10.1002/chem.200701776
日期:2008.3.27
A novelroute towards the polyhydroxylated pyrrolizidine alkaloid (+)-alexine has been developed. A key step in this synthesis is a highly stereoselective [3+2] annulation reaction of N-Ts-alpha-amino aldehyde 7 a (Ts=tosyl) and 1,3-bis(silyl)propene 8 a for the construction of the polyhydroxylatedpyrrolidine subunit of the target molecule. Previous synthetic strategies rely on carbohydrates that