Stereoselective Synthesis of (2E,4E)- and (2Z,4E)-2,4-Alkadienoates by the Ester Enolate Claisen Rearrangement of (E)-1-Alkyl-3-trimethylsilyl-2-propenyl Glycolates Followed by the Peterson Reaction

The ester enolate Claisen rearrangement of (E)-1-alkyl-3-trimethylsilyl-2-propenyl glycolates gave (E)-erythro-2-hydroxy-3-trimethylsilyl-4-alkenoates with high diastereoselectivity, which were stereoselectively converted into (2E,4E)- and (2Z,4E)-2,4-alkadienoates by the Peterson reaction.