Starter Groups Other Than Acetate

In the examples so far discussed, the basic carbon skeleton has been derived from an acetate starter group, with malonate acting as the chain extender. The molecule has then, in some cases, been made more elaborate by the inclusion of other carbon atoms, principally via alkylation reactions. However, the range of natural product structures that are at least partly derived from acetate is increased enormously by altering the nature of the 

Michael-type nucleophilic addition on to a, f -unsaturated ketone 

Flavonoids and stilbenes are simple examples of molecules in which a suitable cinnamoyl-CoA C6C3 precursor from the shikimate pathway (see 

Fatty acyl-CoA esters are similarly capable of participating as starter groups. Fatty acid 

Poison oak Rhus toxicodendron or Toxicodendron toxicaria Anacardiaceae) is nearly always found as a low-growing shrub, and has lobed leaflets similar to those of oak. It is also common throughout North America. There appears considerable confusion over nomenclature, and Rhus radicans may also be termed poison oak, and R. toxicodendron oakleaf poison ivy. Poison oak contains similar urushiol structures in its sap as poison ivy, though heptadecylcatechols (i.e. C17 side-chains) predominate over pentadecylcatechols (C15 side-chains). 

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