Dr N R Krishnaswamy has over 30 years of teaching experience in institutions such as the All India Institute of Medical Sciences, New Delhi, University of Delhi, Bangalore University, Calicut University and Sri Sathya Sai Institute of Higher Learning, where he was Professor and Head, Department of Chemistry.

1 Introduction 1.1 Th e terpenes 1.2 Th e alkaloids 1.3 Flavonoids and related compounds 1.4 Xanthones 1.5 Other oxygen heterocyclic compounds 1.6 Quinonoid compounds 1.7 Lichen metabolites 1.8 Concluding remarks 2 Structure 2.1 Introduction: A survey of the methods used for determination of structures 2.2 Strychnine: A hard nut to crack! 2.3 Nepitrin and pedaliin: A case of mistaken identity! 2.4 Colchicine: Structure from ‘armchair’ research! 2.5 Longifolene: A molecular acrobat! 2.6 ß-amyrin: A ‘straight’ molecule 2.7 Wedelolactone: Th e fi rst of the coumestans 2.8 Protoaphin-fb : An insect pigment 2.9 Tylophorine: Another ‘straight’ molecule with a kink or two! 2.10 Heliangine: An anti-auxin 2.11 Delphisine: Confi rmation of a structure by NMR spectra 2.12 Tubocurarine: Th e sting in the arrow 2.13 Sclerophytins A and B: Cytotoxic diterpenes from marine coral 2.14 Mangiferin: Parent of the Indian yellow 2.15 Conessine: A pseudo alkaloid 3 Stereochemistry 3.1 Introduction 3.2 Absolute stereochemistry of morphine 3.3 Quinine and related alkaloids 3.4 Emetine 3.5 Enhydrin 3.6 Conformations of naturally occurring germacranolides 3.7 Stereochemistry of rotenoids 3.8 Lactone fusion in sesquiterpene lactones 3.9 Stereochemistry of abietic acid 3.10 Catechins 3.11 Sphingosine 3.12 Stereochemistry of menthol 3.13 Stereochemistry of the kamahines 3.14 Absolute confi guration of benzyl isoquinoline alkaloids 3.15 Stereochemistry of some indole alkaloids 4 Reactions and Rearrangements 4.1 Introduction 4.2 Rearrangement reactions of morphine 4.3 Smaller and more agile molecular acrobats 4.4 Th e Wesley–Moser rearrangement 4.5 Some interesting reactions of reserpine 4.6 Molecular yoga: Reactions of papaverine 4.7 Two examples of transannular reactions 4.8 Th e epoxide as a medium of articulation 4.9 Capillarisin: An example of SN2 displacement 4.10 Th e reverse of a transannular cyclisation 4.11 Th e epoxide group as a ‘handle’ for conversion 4.12 Reactions of linalool 4.13 Th e Nametkin rearrangement 4.14 Reactions of caryophyllene 4.15 Santonin to desmotroposantonin: An example of dienone–phenol rearrangement 5 Synthesis 5.1 Introduction 5.2 Synthesis of polyoxygenated fl avones with uncommon oxygenation patterns 5.3 Two contrasting syntheses of anthracyclinones 5.4 An approach to quassinoid synthesis 5.5 Synthesis of a semiochemical 5.6 A synthesis of polygodial 5.7 Balsamiferone and gravelliferone 5.8 Gyrinal: Defensive secretion of an insect 5.9 Synthesis of an unusual methylthiophenanthrene diol 5.10 A synthesis of (-) khusimone 5.11 Synthesis of a chiral marine natural product 5.12 A biomimetic synthesis of morphine 5.13 Synthesis of ergocristine 5.14 A stereoselective synthesis of reserpine 5.15 Synthesis of a paraconic acid 6 Biosynthesis 6.1 Introduction 6.2 Biosynthesis of some benzylisoquinoline alkaloids 6.3 Reticuline to morphine 6.4 From phenylalanine to colchicine 6.5 Tryptophan to quinine 6.6 Biosynthesis of some indole alkaloids 6.7 Biosynthesis of ergot alkaloids 6.8 Evolution of the monoterpenes 6.9 From mevalonic acid to the sesquiterpenes 6.10 Biosynthesis of some diterpenes 6.11 A brief note on the biosynthesis of ophiobolins 6.12 Geranyl pyrophosphate to lanosterol and the triterpenes 6.13 Non-nitrogenous secondary metabolites from shikimic acid: Flavonoids and related polyphenols 6.14 Biosynthesis and transformations of isofl avones 6.15 Biosynthesis of anthraquinones 7 Biological Significance of Secondary Metabolites 7.1 Introduction 7.2 Semiochemicals: An overview 7.3 Insect pheromones 7.4 Plant–insect interactions 7.5 Plant–vertebrate interactions 7.6 Plant–plant interactions 7.7 Plant–microbe interactions 7.8 Phytoalexins 7.9 Insect–animal interactions 7.10 Defensive secretions of insects 8 Problems Index