α,β-unsaturated lactone derivatives are very important structural core which are isolated from nature and shown as source for several biological activities. Biologically active styryl δ-lactones are well known α,β-unsaturated-δ-lactones. Up to date, many α,β- unsaturated-δ-lactones and their analogues have been isolated and synthesized, exhibiting promising anti-proliferative properties against different cancer cell lines. In this thesis, large scale asymmetric syntheses of (R)-4’-methylklavuzon and (R)- 2’-methylklavuzon were completed successfully. Also, syntheses of heteroatom functionalized naphthyl substituted novel α,β-unsaturated-δ-lactone (5,6-dihydro-2Hpyran- 2-one) derivatives, α,β-unsaturated-γ-lactone (furan-2(5H)-one) derivatives and 7- membered α,β-unsaturated lactone (6,7-dihydro-5H-oxepin-2-one) derivatives were accomplished. Development of a method for one-pot synthesis of 6-membered α,β-unsaturated- δ-lactone was also studied, and a new vinylogous aldol addition method was developed. By this method, new α,β-unsaturated methyl esters were prepared via dienolate formation starting with methyl buten-3-oate.