title: Two-carbon homologation of aldehydes and ketones to α,β-unsaturated aldehydes.
abstract: Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the reagent with the starting aldehyde, followed by removal of the dimethylhydrazone protective group with a biphasic mixture of 1 M HCl and petroleum ether. This robust two-step process worked with a variety of aldehydes and ketones. Overall isolated yields of unsaturated aldehyde products ranged from 71% to 86% after the condensation and deprotection steps.
authors.affiliation: Unit of Crop Bioprotection Research, USDA Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N. University Street, Peoria, IL 61604, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Petroski
authors.forename: Karl
authors.initials: K
authors.lastname: Vermillion
authors.forename: Allard A
authors.initials: AA
authors.lastname: Cossé
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D063065:Organophosphonates / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D007659:Ketones; D063065:Organophosphonates; D002244:Carbon