# A Concise Total Synthesis of Tryprostatins A and B and Epimers

## TL;DR

Scientists developed a short and efficient method to synthesize two natural compounds, tryprostatins A and B, along with their mirror-image versions.

## Contribution

A four-step synthesis of tryprostatins A and B using quinine as a bifunctional base is introduced.

## Key findings

- The synthesis starts from commercially available gramine and includes a key coupling step mediated by quinine.
- The method produces tryprostatins A and B and their epimers in 1:1 ratios with overall yields of 22% and 44%.
- The epimers were isolated and separated using column chromatography.

## Abstract

A concise four-step
total synthesis of tryprostatins
A and B has
been developed, starting from commercially available gramine. The
key step features a coupling between a C2,N′-diprenylated gramine salt and a diketopiperazine
mediated by quinine as a bifunctional base. The synthesis afforded
tryprostatins A and B along with their respective epimers in 1:1 ratios
as determined by isolation and separation via column chromatography.
The overall combined yields were 22% for tryprostatin A and its epimer
and 44% for tryprostatin B and its epimer.