New methods for the preparation of 1-alkenyl ethers and sulfides using di- and tri-thioorthoformates

The treatment of carbonyl compounds with the organotitanium species formed from methoxybis(phenylthio)methane and low valent titanium species Cp 2 Ti[P(OEt) 3 ] 2 gave 1-alkenyl ethers in good yields. 1-Alkenyl sulfides were also obtained by the similar reaction using triphenyl trithioorthoformate. These reactions were successfully applied to carboxylic esters and thiolesters to produce 1,2-diheteroatom substituted 1-olefins.