Hydrogen Peroxide → HCID 6993196, compound

Participants

Reaction Steps

As disclosed in Pearce et al., J. Chem. Ecol., 1, p 115 (1975), this compound is known to be a component of the pheromone of the European elm bark beetle, Scolytus multistriatus. The present synthesis began with (+)-pinanediol propane-1-boronate, which was converted to (+)-pinanediol (1S)-1-chlorobutane-1-boronate by the procedure outlined in Example 1. This compound was then treated with methylmagnesium bromide (stoichiometric amounts of reactants were used, with 60 ml of tetrahydrofuran solvent for 24 mmol), and kept at 20° C. overnight. The isomeric purity of the (+)-pinanediol (2S)-pentane-2-boronate was confirmed by oxidation with alkaline hydrogen peroxide to (S)-2-pentanol, rotation [α]25 589 +12.86° (c 1.5%, ethanol), which corresponds to 98.2% enantiomeric excess, 99.1% diastereomeric purity of the precursor. (+)-Pinanediol (2S)-pentane-2-boronate was converted to (+)-pinanediol (1S,2S)-1-chloro-2-methylpentane-1-boronate by the procedure outlined in Example 1. This compound was then treated with ethylmagnesium bromide as described above to yield (+)-pinanediol (3S,4S)-4-methylheptane-3-boronate. This material which was chromatographed on silica with 20% ethyl acetate in hexane and distilled in a short path apparatus under high vacuum, and which was prepared in a yield of 86.5% (based on the pentane-2-boronate), was oxidized with alkaline hydrogen peroxide to yield (3S,4S)-4-methyl-3 -heptanol, bp 102°-104° C. (95 torr), [α]24 589°-19.84° (c 4.4%, hexane). Attempts to detect any diastereomer by standard NMR methods failed. Properties reported for this compound in Mori, Tetrahedron, 33, pp 289-294 (1977) are bp 105°-108° C. (102 torr), [α]22D -21.7° (c 0.57%, hexane).

Provenance & Evidence