SYNTHESIS OF FOUR n-ALKANES WITH TERMINAL DIPOLAR SUBSTITUENTS

Article abstract of DOI:10.1016/S0040-4020(01)89937-3

12-Nitrododecanol, 1,12-dinitrododecane, 1,24-dinitrotetracontane and 2,15-diaminohexadecan-1,16-dioic acid were prepared from the common intermediate 12-bromododecanol.This bromoalcohol, being prepared from cyclododecanone, is free of homologous bifunctional impurities.The functionalised 24 carbon chain was prepared by a Wittig reaction of 12-bromododecanal with the triphenylphosphonium salt of 12-bromododecanal ethylene acetal using 'naked' carbonate anion to provide the base.The resulting bromoacetal was converted to 24-bromotetracont-12-enol, both this and the 12-bromododecanol were converted to the corresponding α,ω-di-iodides and then to the desired α,ω-dinitro compounds.The α-amino acid functionality can be introduced on an α,ω-dihalide with the anion of either diethyl 2-acetylaminopropan-1,3-dioate or benzylidene glycine ethyl ester.Also detailed is the previously unreported reduction of a carboxylic acid to an alcohol by borane-dimethyl sulphide in dichloromethane.