Computer-assisted retrosynthetic

CHAOS is a program for the computer-assisted design of organic synthesis. CHAOSBASE is an auxiliary program, which makes it possible to create retrosynthetic reactions data bases that can then be used by the CHAOS program. 

The computer-assisted synthetic analysis designated OCSS (organic chemical simulation of synthesis) and LHASA (logic and heuristics applied to synthetic analysis) were designed to assist chemists in synthetic analysis by Corey et LHASA generates trees of synthetic intermediates from a target molecule by analysis in the retrosynthetic direction. 

A similar computer-assisted approach was also elaborated envisioning the choice of the Diels-Alder transform as a strategic reaction. The task of the program in this case is to suggest the retrosynthetic transformations of the target structure leading to the creation of the cyclohexene moiety amenable to the retro-Diels-Alder disconnection. The general coiu e of these pursuits is shown in Scheme 3.50. ... 

The Corey-Wipke approach considered above actually represents a backward computer-assisted search of synthetic pathways, which is set up as an interactive procedure with the operator helping to guide the selection of the most promising routes. In this approach the computer is assigned to the job of accumulation, storage, and processing of all chemical information amenable to formalization, while the chemist is supposed to make a final evaluation of the suggested retrosynthetic solutions and to control the direction of further searches. 

Retrosynthetic Analysis. An approach to computer-assisted synthesis design that starts with the products of a reaction or sequence of reactions and works backwards toward the reactants. An example program that implements retrosynthetic analysis is the LHASA program of E. J. Corey s group. 

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. 

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