Group addition, functional

Subgoal requests can be combined and mixed according to the situation. Next to be added is PGI then INTRO since not all groups may be INTRO ed. 

Four ring forming transforms have been considered at length by the LHASA development group - the Diels Alder addition, the Robinson Annelation, the Simmons-Smith reaction, and iodo-lactonization. The first three of these have been fully implemented in LHASA and the fourth is completely flow charted and awaits only coding into the chemistry data base language. 

ACS Symposium Series American Chemical Society Washington, DC, 1977. 

All ring chemistry tables are organized into what is called binary search trees. Queries are posed about the existence of certain structural features. Each of these questions is answerable with a yes or a no. Based on the answer one of two different followup questions is selected. Embedded within the table may be requests for subgoals, either those already in the PGI or PGA table or for special reactions which are needed only for these transforms and are not of general synthetic interest. 

The example below shows some of the synthetic routes generated by the Diels Alder transform for the indicated precursor. It is important to note that while some of the chemistry may look somewhat naive, it can be quite thought provoking. 

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Functional group addition or substitution reactions at C-4 have produced a variety of bisindole derivatives, and structure modifications at this position are often accompanied by unexpected shifts in biological activity. As a result these studies have produced several compounds with intriguing biological properties. 

As terminal alkynes and ethynyl alcohols are the convenient sources to generate ruthenium vinylidene and allenylidene intermediates, many carbocyclizations have been achieved via nucleophilic addition and other activations at the two intermediates. Most reported carbocyclizations appear to be synthetically useful, not only because of their chemoselectivities but also because of their tolerance toward organic functional groups. Additional examples of catalytic carbocyclization based on ruthenium vinylidenes are still growing, and on the basis of the concepts developed here one can expect to see many new applications in the near future. 

SUMMARY OF RETROSYNTHETIC STRATEGIES Functional group addition (FGA) (methods 1, 2 and 3)... 

Functional Group Addition Illustrated by Friedel-Crafts Alkylation... 

The preliminary to the corresponding disconnection is the addition (imaginary) of a functional group where there was none. We call this FGA (functional group addition). The corresponding... 

FUNCTIONAL GROUP ADDITION (a) STRATEGY OF SATURATED HYDROCARBON SYNTHESIS. 

While carboxylic acids are among the most acidic of all organic compounds, we are more frequently interested in removing protons that are not directly associated with the carboxylic acid functional group. Additionally, reliance upon removal of protons from molecules containing functional groups other than carboxylic acids is common. In this context, esters represent the next functional group we will study. 

Dicarbonyl 39 is quite effective in promoting the reductive coupling of carbonyl or imino functional groups. Addition of diethyl ketomalonate to solutions of 39 yields 43 (116). 

Addition or removal of functional groups Addition of functional groups to double bonds or their removal to form... 

When cooperativity is ignored, contributions of AG valnes to the total free energies of binding may be added together. Approaches based on functional group additives equation (21.7) or the additivity of free enthalpy components equation (21.8) have freqnently been applied to understand and predict protein-ligand interactions. Pioneering studies in this held were performed by Andrews et al. and Lau and Pettitt. ... 

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