BACKROUND MATERIAL. Sources, Production Pathways, and Pricing of Industrial Organic Chemicals. ALIPHATIC BUILDING BLOCKS. C 1 Building Blocks. C 2 Building Blocks. C 3 Building Blocks. C 4 Building Blocks, Including Isoprene and Cyclopentadiene. C 5 and Higher Acyclic Building Blocks. CYCLIC BUILDING BLOCKS. Nonaromatic Carbocyclic Compounds. Aromatic Carbocyclic Compounds. Heterocyclic Building Blocks. Index.