method with CDMT enabled the sequential transformation of gramines: substitution with (N-alkylidene)aminomalonates followed by the Pictet–Spengler reaction under acidic conditions afforded 1,2,3,4-tetrahydro-β-carboline derivatives in one pot.
A practical and short synthesis of a novel antibiotic, (±) indolmycin, has been accomplished. The overall process requires only 4 chemical steps by starting from gramine derivative 3 and oxazolinone 2.