41. This substituent improves aqueous solubility and potency by limiting the conformational freedom of the inhibitor. 42. Fluorine is a deactivating meta direction substituent . 43. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring. 44. The net electron flow from or to the substituent is determined also by the inductive effect. 45. Some of the most effective directing substituent groups are alkoxy, amido, sulfoxide, sulfonyl. 46. This transition state has a gauche interaction between the peroxyacid and the non-migrating substituent . 47. It is a derivative of pyridine with a carboxylic acid substituent at the 4-position. 48. The substituent groups may be divalent or trivalent, yielding ions such as iminium and nitrilium. 49. If you like indanone as the parent structure, then the substituent is a benzylidine derivative. 50. The peripheral amine groups are modified by a substituent X which often is a protection group.
