Synthesis of nonracemic 2,3,6-trisubstituted piperidine derivatives from sugar lactones via tandem Wittig [2+3] cycloaddition reaction. A novel entry to Prosopis and Cassia alkaloids
作者:Claus Herdeis、Thomas Schiffer
DOI:10.1016/s0040-4020(98)01085-0
日期:1999.1
azido lactol 7 proceeds with concomitant 1,3-dipolarcycloaddition of the azido function to the α, β-unsaturatedester function of 9a,b which can not be isolated. The diastereomeric triazolines 10a,b and the diazoamines 11a,b were separated. The vinylogous urethane 13 can be hydrogenated diastereoselectively to the all-cis configurated piperidyl acetic ester derivative 14 which is deprotcted to 1. Functional