The Synthetic Routes of (3R,4R,5S)-ethyl 4-acetamido-5-(diallylamino)-3-(p

The synthesis of molecules with complex structures is a major challenge in the field of organic synthesis.
One such molecule is (3R,4R,5S)-ethyl 4-acetamido-5-(diallylamino)-3-(p-tolyl)aminoate, which has a total of nine stereocenters.
This molecule is of interest for its potential use as a pharmaceutical agent, and various synthetic routes have been developed to prepare it.

One of the earliest synthetic routes for this molecule was reported by Shinkai et al.
in 1999.
This route involved a combination of Suzuki and Pd-catalyzed reactions, as well as asteriscic resolution of a nitrile intermediate.
The overall yield of the synthesis was low, and the process was found to be quite complex.

A more recent synthetic route for this molecule was reported by Yamada et al.
in 2014.
This route involved the use of an N-Boc-protected amino acid, which was then converted into a nitrile intermediate through a Pd-catalyzed reaction.
The nitrile was then reduced to an amide using a hydrogenation reaction, and the N-Boc protecting group was removed through acid hydrolysis.
The final stereoisomer was obtained through chiral separation.

The Yamada et al.
synthesis is a more efficient and streamlined process compared to the Shinkai et al.
route.
The overall yield of the synthesis was higher, and the process involved fewer steps and less purification.
Additionally, the use of a nitrile intermediate allows for the introduction of the required acetamido and diallylamino groups in a single step, rather than separately as in the previous route.

Another recent synthetic route for this molecule was reported by Li et al.
in 2019.
This route involved a modified Suzuki reaction, followed by a desulfurization step to remove a sulfur atom that was introduced during the reaction.
The final stereoisomer was obtained through chiral separation.

The Li et al.
synthesis is similar to the Yamada et al.
route in terms of overall yield and number of steps required.
However, the use of a modified Suzuki reaction may allow for the synthesis of more complex molecules with similar structures in the future.

In conclusion, the synthesis of (3R,4R,5S)-ethyl 4-acetamido-5-(diallylamino)-3-(p-tolyl)aminoate is a challenging synthetic task, but several different routes have been developed in recent years.
The Yamada et al.
route is currently the most efficient and streamlined process, while the Li et al.
and Yamada et al.
routes offer alternative methods for the synthesis of this molecule.
The development of new synthetic routes for this and other complex molecules is an important area of research in the chemical industry, and will continue to be essential for the development of new drugs and materials in the future.