A new series of chiral materials, hexyl(2s)-2-(6-(-4-(4′-alkoxyphenyl)benzoyloxy)-2′-naphthyl)propionates (HmPBNP;m= 6-18) had been prepared and their liquid crystalline properties were investigated as a function of alkyl chain length. These chiral materials exhibited novel ferroelectric Sc* and antiferroelectric ScA* phases and a propensity to the formation of the ScA* phase was found at longer alkyl chain lengths (m= 10, 12 - 18). An odd-even effect of the threshold voltage as a function of alkyl chain length for compounds HmPBNP (m= 12-16) possessing antiferroelectricity was observed. Spontaneous polarization and transverse dipole moment were also measured and are discussed in terms of the elongated alkyl chain length.