Starting from succinic anhydride and 2-methylanisole, a chemoenzymatic collective formal/total synthesis of several optically active tetrahydronaphthalene based bioactive natural products has been presented via advanced level common precursors; the natural product and antipode (-)/(+)-aristelegone B. Regioselective benzylic oxidations, stereoselective introduction of hydroxyl groups at the α-position of ketone moiety in syn-orientation, efficient enzymatic resolutions with high enantiomeric purity, stereoselective reductions, samarium iodide induced deoxygenations and tandem acylation-Wittig reactions without racemization and/or eliminative aromatization were the key features. An attempted diastereoselective synthesis of (±)-vallapin has also been described.

Starting from dimethyl (±)-2-hydroxy-3-methylenesuccinnate chemoenzymatic collective formal/total synthesis of enantiomerically pure bioactive natural products has been described via the advanced level common precursor (+)-artabotriol. An efficient enzymatic resolution with high enantiomeric purity, selective diester to diol reduction, and requisite dehydrative coupling reactions without any racemization are the significant topographies.

Starting from putrescine and the requisite carboxylic acids, first syntheses of bioactive natural products gigantamide A, dasyclamide, and cucullamide were accomplished in very good overall yields using an appropriate sequence of dehydrative coupling reactions. The syntheses of the corresponding dehomo analogues of these natural products are also described. Regioselective diisobutylaluminum hydride reduction of an unhindered carbonyl group in citraconimide is the key step.

Selective reduction of 3-(4-hydroxyphenyl)-2-methylmaleic anhydride provides access the corresponding γ-hydroxybutenolide natural product yangjinhualine A.

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