Retrosynthetic tree

The input/output driver is also used for the (retro)synthetic tree inspection. The user can walk through the tree generated, inspect the selected nodes, edit them, and submit them for further processing by the SPS generator, thus creating new branches and levels of the (retro)synthetic tree. Each node of the (retrosynthetic trees stores not only the two-dimensional structure of the chemical compound, but also the distance from its father (i.e starting structure) measured by the reaction as well as chemical distances, and also its fragmentation level, measured by its order. 

Construct a retrosynthetic tree based on the given template as a starting material. 

Each reference discusses a proposed biosynthetic pathway for the molecule shown. Construct a retrosynthetic tree based on that pathway and then show the total synthesis. 

There are a number of computer programs which can assist the synthetic chemist in the retrosynthetic analysis of a target compound. One that is specifically designed to be applied to the synthesis of chiral compounds is the CHIRON program, developed at the University of Montreal by Professor Steve Hanessian. CHIRON does not generate a full retrosynthetic tree but rather yields readily available starting materials from the Chiral Poof that contain the chirality needed to construct the product in optically pure form. 

The target molecule is now entered and ready for synthetic analysis. The molecule may be saved in a disk file with the WRITE command so the work of input will not be lost in the event of telephone disconnection. It can be read back in by a READF command. To begin analysis with the standard default strategies (which will be described later) the user simply types RUN or pushes light button "PROCESS. This generates the first level of the retrosynthetic tree. Each precursor is shown to the user on his terminal. He is then free to VIEW a precursor and PROCESS it further. Thus the standard usage of SECS is quite simple for the user. 

The obtained retrosynthetic tree looks like this ... 

At the second level of the retrosynthetic tree appear again the syn-thons with the structure of ketenes, vinylethers (vinylacetates), derivatives of cinnamic acid, 1,2-dioxo compounds, isocyanates, and going deeper in the fragmentation we meet phenylacetylene and "exotic carbene intermediates. 

A siynthestis tree is the graphical representation of the result of a retrosynthetic analysis. The target compound (T) is set to the top of a tree that is turned upside down (Figure 10..3-3.3). 

Ex-Target Tree. (EXTGT Tree) A branching tree structure formed by retrosynthetic analysis of a target molecule (treetop). Such trees grow out from a target and consist of nodes which correspond to the structures of intermediates along a pathway of synthesis. 

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