Functional group syntheses using

Organic Synthesis Functional Group Transformations Using Sn2 Reactions... 

Thorpe-Ziegler synthesis of 3-aminoindoles with additional functional groups was used as part of the synthesis of condensed indoles [e.g., azepines (94) were obtained from 3-amino-2-benzoylindoles (93) (91JHC379) (Scheme 24)]. In these cases the nature of the substituent R is important for a smooth reaction (Ac < Bz < 2-N02-benzoyl, but no reaction when R = H). With 2-chloro-3-(/V-bromoacetyl-/V-methylamino)pyridine and o-benzoylaminobenzonitriles (95), the condensed pyridodiazepinones 97 and 99 (95H753) were obtained via intermediates 96 and 3-aminoindoles intermediate (via 98) 3-aminoindoles followed by substitution of the 2-chloro substituent by the resulting 3-amino group (Scheme 25). 

Unsubstituted sulphamide NH2S02NH2 has recently been reported to be useful in functional group synthesis. Reaction of sulphamide with acid chlorides leads to a one-pot synthesis of nitriles 402378 (equation 132). The reaction is successful for a large variety of aliphatic and aromatic acid chlorides with electron-withdrawing and electron-donating substituents. Sterically hindered as well as heterocyclic nitriles are also obtained in high yields. The reaction is considered to proceed via the iV-acylsulphamide, which is further enolized and cleaved to yield the nitrile 402 and sulphamic acid. 

Economy of reactions Joining monomers to make macromolecules is economical if the monomers can be joined by the same chemistry. If the monomers contained different functional groups, synthesis of each polymer would require a different kind of catalyst for each monomer added to the chain. Clearly, it is more economical to use a generic catalyst to put together each of the many monomers required for synthesis. 

The synthesis of ACECs involves the well-known methods of preparation of CECs and glycidyl ethers. Cycloolefins with various functional groups are used as the starting materials. 

ORGANIC SYNTHESIS FUNCTIONAL GROUP TRANSFORMATIONS USING Sm2 REACTIONS... 

The next example uses another carbon electrophile how can you use the relationship of the two functional groups in TM 249 to design a synthesis of the molecule ... 

The formal carbanions and carbocations used as units in synthesis are called donor synthons and acceptor synthons. They are derived from reagents with functional groups. 

Pharmaceutically useful steroids may be either obtained by total synthesis or by degradation and functional group conversions from inexpensive natural steroids. Both approaches will be discussed in this section (H. Langecker, 1977 R.T. Blickenstaff, 1974). 

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