4-Propylcyclohexanone → HCID 23443725, compound

Participants

Reaction Steps

A mixture of 5 mmol of methyltriphenylphosphonium bromide and 5 mmol of butyllithium in 25 ml of tetrahydrofuran which has been reacted to completion at 0° C. was treated over the course of 10 minutes with a solution of 4.5 mmol of 4-propyl-2-(3,4,5-trifluorobenzylidene)cyclohexanone [prepared from 4-propyl-cyclohexanone and 3,4,5-trifluorobenzaldehyde analogously to Walton, J. Org. Chem. 22, 1161 (1957)] in 5 ml of tetrahydrofuran. After 4 hours at room temperature, 50 ml of water were added, the mixture was extracted twice with 25 ml of tert-butyl methyl ether each time, the extract was washed with water and evaporated in a rotary evaporator, and the residue was chromatographed over silica gel with heptane. The resultant crude product [(Z2) from Scheme 1 with R1=propyl, L2=L3=F, X═F) was dissolved in 1 l of benzene and irradiated with a 450 W UV lamp with cooling in a circulation apparatus. After 8 hours, the reaction solution was evaporated in a rotary evaporator, and the residue was chromatographed over silica gel with heptane/ethyl acetate 9:1. Recrystallization from acetonitrile gave colorless crystals.

Provenance & Evidence