LHASA synthetic analysis

In 1969 Corey and Wipke [7] reported the program OCSS (Organic Chemical Simulation of Synthesis) which was the precursor of one of the most powerful programs known at present which has been named LHASA (the acronym of Logic and Heuristics Applied to Synthetic Analysis) [5b] [8]. Since then, different... 

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. 

Series 61, American Chemical Society, Washington, DC, 1977, pp. 1-32. LHASA—Logic and Heuristics Applied to Synthetic Analysis. 

Socorro et al, 2005) and the LHASA (Logic and Henristics Applied to Synthetic Analysis) software (see URL). However, the cnrrent solntions to chemical reaction prediction have several limitations. Secondary and tertiary interactions are rarely considered and there is httle work on chemistry reasoning which is valrrable for chemical stability analysis bnt would reqtrire an exphcit irrformation model. In additiorr, there is little scope for integration of the reaction irrformation (which might describe conditions in microsolutiorts found between solid particles) with the solid information. 

Logic and Heuristics Applied to Synthetic Analysis (LHASA) is an expert system for synthesis planning that assists chemists in designing efficient routes to target molecules for organic synthesis. 

Logic and Heuristics Applied to Synthetic Analysis for retrosynthetic analysis of organic compounds using reactions stored as transforms in knowledge base. APSO, a teaching version of LHASA that displays successful and unsuccessful... 

Research into the use of digital computers to assist in the derivation of synthetic routes to complex molecules has been in progress for several years at Havard. The program is called LHASA Logic and Heuristics Applied to Synthetic Analysis). The research is being carried out by a team headed by Corey. l... 

LHASA—Logic and Heuristics Applied to Synthetic Analysis... 

Despite the wealth of knowledge about various chemical reactions, there exists no formal framework of interrelationships to guide the chemist in the synthesis of even moderately complex molecules. The LHASA (Logic and Heuristics Applied to Synthetic Analysis) project is an attempt to codify and organize the techniques used in organic synthesis. 

The synthetic approach (among others) was suggested by LHASA-10, the Harvard program for computer-assisted synthetic analysis. For some reading see Corey, E. J. Quart. Rev., Chem. Soc. 1971,25, 455. 

The evolution of molecular graphics (7) is described in an earlier ACS Symposium Series book (77) which acts as an interesting precursor to this present volume. Chemical reaction systems such as LHASA (Logic and Heuristics Applied to Synthetic Analysis) 18) and SECS (Simulation and Evaluation of Chemical Synthesis) (79) had long used graphics but it was some time before the first in-house, proprietary system appeared, attracting much interest in the chemical and pharmaceutical industries. This was Upjohn s Compound Information System, COUSIN 20-21). 

As a check on the effectiveness of the LHASA program, the authors performed an analysis on 14 polycyclic compounds for which a synthesis was already reported in the literature. In 10 of these cases, the LHASA program included in the set of the generated solutions the very synthetic schemes that had been successfully realized. 

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