Bromide ion → HCID 19847213, compound

Participants

Reaction Steps

The novel synthesis of racemic 6,12-dimethylpentadecan-2-one is shown in FIG. 4 and described in detail below in Example 2. Briefly, the synthesis of racemic 6,12-dimethylpentadecan-2-one was initiated by the reaction of methylcyclopropyl ketone with n-propylmagnesium bromide. The intermediate tertiary carbinol was isomerized to the homoallylic bromide (1) with hydrobromic acid. The allic bromide (1) was reduced to 1-bromo-4-methylheptane (2) by hydrogenation with PtO2. The saturated bromide (2) was converted to the corresponding organocopper reagent which was reacted with methyl vinyl ketone in the presence of tri-n-butyl phosphine to produce 8-methylundecan-2-one (3). A Wittig reaction between the C-12 methylketone (3) and ethylene ketal pentan-2-one phosphonium salt (4), produced a mixture of the Z and E isomers of the ethylene ketal of 6,12-dimethyl-(5) (15% yield). The unsaturated ethylene ketals were hydrogenated and then subjected to acid hydrolysis to produce 6,12-dimethylpentadecan-2-one (7). The final product was purified by high-performance liquid chomatography (HPLC) and GLC.

Provenance & Evidence