A New and Convenient Preparation of Conjugated Dienals

Article abstract of DOI:10.1246/bcsj.63.3601

For preparation of 5-monosubstituted or 5,5-disubstituted 2,4-dienals, 1-(methylthio)-5-(p-tolylsulfonyl)-1,3-pentadiene (4) is revealed to be an important precursor.When 5-(methylthio)-5-(p-tolylsulfonyl)-1,3-pentadiene, that is easily obtainable from (methylthio)methyl p-tolyl sulfone, was treated with silica gel, 1,5-rearrangement of p-tolylsulfonyl group occurred to give 4.The conditions for mono- or dialkylation of 4 followed by hydrolysis leading to the dienals are desribed.