Stereoselective Acetalization for the Synthesis of Liquid-Crystal Compounds Possessing a <i>trans</i>-2,5-Disubstituted 1,3-Dioxane Ring with Saturated Aqueous Solutions of Inorganic Salts
for the synthesis of trans-2,5-disubstituted 1,3-dioxane derivatives, which are important liquid-crystal compounds, was developed. The acetalization reaction between aldehydes and 2-substituted 1,3-propanediols in the presence of acids gave the corresponding 2,5-disubstituted 1,3-dioxane derivatives with high trans selectivity (trans/cis = >96:<4), when the reaction was performed with saturated aqueous
A thiadiazole compound represented by the formula (I):
wherein R is a hydrogen atom, an optionally substituted C1-C7 chain hydrocarbon group etc., Z is an oxygen atom or a sulfur atom, X is a —NR
2
R
3
group etc., R
2
and R
3
each independently are a hydrogen atom, a C1-C4 alkyl group, a C3-C4 alkenyl group, a C1-C4 alkoxy group, or a phenyl group, or R
2
and R
3
bind to each other at the ends thereof to form a C2-C7 alkanediyl group, has excellent controlling effect on a noxious arthropod.