Hydrochloric Acid → HCID 68773038, compound

Participants

Reaction Conditions

Reaction Steps

At 5° C., a solution of allylmagnesium chloride (12.1 ml, 2 M in THF) was treated dropwise with a solution of rel-(6S,7S)-ethyl 7-methylspiro[4.5]dec-9-ene-6-carboxylate (1.5 g, 6.7 mmol, prepared as described in Example 19) in THF (20 ml), stirred at 20° C. for 1 h, poured into cold 2N aqueous HCl (30 ml), and extracted twice with MTBE (70 ml). The combined organic phases were washed with water (100 ml), with a saturated aqueous solution of NaCl (100 ml), dried (MgSO4), and concentrated. The crude product (1.9 g) was dissolved in DMF (10 ml) and added to a solution of KOt-Bu (1.2 g, 10.7 mmol) in DMF (10 ml). The resulting mixture was stirred for 1 h, poured into cold 2N aqueous HCl (30 ml), and extracted twice with hexane (80 ml). The combined organic phases were washed with water (100 ml), with a saturated aqueous solution of NaCl (100 ml), dried (MgSO4), and concentrated. The crude product (1.9 g) was then dissolved in toluene (15 ml) and treated with PTSA.H2O (15 mg, 0.077 mmol). The resulting solution was stirred at 60° C. for 2.75 h, poured into cold water (30 ml), and extracted with cyclohexane (20 ml). The combined organic phases were washed with a saturated aqueous solution of NaCl (20 ml), dried (MgSO4), and concentrated. FC (120 g SiO2, hexane/MTBE 25:1) of the crude product (1.38 g) gave (E)-1-(rel-(6S,7S)-7-methylspiro[4.5]dec-9-en-6-yl)but-2-en-1-one (0.63 g, 43%). Boiling point: 115° C. (0.09 mbar).

Provenance & Evidence