Water → HCID 131710942, compound

Participants

Reaction Steps

A solution of 2-(6-carboxyhexyl)-3-nitromethylcyclopentan-1-one methyl ester (20 g) in sodium hydroxide (10%, 61.6 ml) and methanol (40 ml) is stirred overnight, dilited with water (140 ml), and added to a mixture of concentrated sulfuric acid (18.4 ml) and water (118 ml) maintained -5° to -10° . A small amount of ether is added to keep the compound well suspended in the liquid. After completion of addition the cooling bath is removed and the mixture is stirred for 1 hour, extracted with ether, washed, dried and evaporated under reduced pressure to give a residue containing 2-(6-carboxyhexyl)cyclopentan-1-on-3-al γmaxFilm 2700, 1730 cm-1. This residue is refluxed in methanol (120 ml) containing p-toluenesulfonic acid (3 g) for 1.5 to 2 hours, the solvent evaporated, and the residue extracted with ether, washed with water, dried and evaporated to yield a residue which is passed through silica gel (1 kg) in 20% acetone-hexane to yield the methyl ester of 2-(6-carboxyhexyl)cyclopentan-1-on-3-al dimethyl acetal γmaxFilm 1730, 1124, 1072 cm-1NMR: (CDCl3) 4.25, 3.63, 3.38δ.

Provenance & Evidence