Acetone → (3E,6R)-6,10-dimethyl-3-undecen-2-one

Participants

Reaction Steps

A 3 L 3-necked flask fitted with a reflux condenser, a mechanical stirrer and an argon inlet tube was charged with 161.5 g (1.033 mol) of (R)-3,7-dimethyloctanal (fractions 1-5 from Example 3, GC purity 97.3%). 413 mL of acetone and 1.24L of 1% ag. KOH. The reaction mixture was stirred vigorously and refluxed for 48 hours. The course of the reaction was monitored by GC. The amount of starting material present was 5% after 25 hours and 3.6% after 48 hours. After cooling in an ice bath, the reaction mixture was poured into a separatory funnel containing 200 mL of brine and extracted with 3×800 mL of hexane/ether 1:1 (parts by volume). The combined organic fractions were washed with 300 mL of brine, dried over MgSO4, filtered and evaporated. Vacuum distillation of the residue through a 30 cm Vigreux column afforded (3E,6R)-6,10-dimethyl-3-undecen-2-one in the following fractions:

Provenance & Evidence