PRACTICAL TOTAL SYNTHESIS OF LUOTONIN A BY INTRAMOLECULAR DOUBLE HETERO DIELS-ALDER REACTION

摘要

An intramolecular double hetero Diels-Alder reaction of 7V-(2-cyanoquinolin-3-ylmethyl)-2-tosyloxybenzamide (3c) provided luotonin A (2) in 82% yield. Surprisingly, N-(2-bromoquinolin-3-ylmethyl)-2-tosyloxybenz-amide (4) directly provided luotonin A (2) in 78% yield in the presence of Pd2(dba)3 (5 mol %), dppf (20 mol %), and K2CO3 (6 eq).