Convenient formation of 4-hydroxyalk-2-en-1-one functionality via A knoevenagel-type carbon chain elongation reaction of aldehyde with 1-arylsulfinylalkan-2-one
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Updated: Oct 8, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
J Nokami1, K Kataoka, K Shiraishi
1Department of Applied Chemistry, Faculty of Engineering, Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005, Japan. nogami@dac.ous.ac.jp
Abstract:
A highly functionalized four-carbon unit, 4-hydroxyalk-2-en-1-one functionality [R2CH(OH)CH=CHCOR1], was conveniently prepared by a reaction of an aldehyde (R2CH2CHO) with a 1-(arylsulfinyl)alkan-2-one [ArS(O)CH2COR1] in the presence of diethylamine (Knoevenagel condition). Other functional groups, such as carbonyl and hydroxy groups, in both of the alkyl chains (R1, R2) did not prevent this reaction. This reaction was used to conveniently prepare (+/-)-(11E)-13-hydroxy-10-oxooctadec-11-enoic acid (14), having cytotoxic activity, and its analogues from undec-10-enoic acid in good yield.
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