Hydrochloric Acid → HCID 68725231, compound

Participants

Reaction Steps

The crude methyl 1-methyl-7-oxaspiro[bicyclo[4.1.0]heptane-3,1′-cyclopentane]-2-carboxylate obtained (13 g) was added to a solution of sodium (1.5 g, 64 mmol) in methanol (100 ml) and the resulting mixture was refluxed for 10 h, poured into cold 2N aqueous HCl (100 ml), and extracted twice with MTBE (100 ml). The combined organic phases were washed with water (100 ml), twice with a saturated aqueous solution of NaCl (100 ml), dried (MgSO4), concentrated, and gave crude gave methyl 8-hydroxy-7-methylspiro[4.5]dec-6-ene-6-carboxylate (5.65 g) which was dissolved in dichloromethane (80 ml) and treated at −30° C. with triethylsilane (14.4 ml, 0.1 mol) and with BF3.OEt2 (4.7 ml, 37.8 mmol). The resulting mixture was stirred for 3 h while allowing the temperature to reach 20° C., poured into cold 2N aqueous NaOH (80 ml), and extracted twice with MTBE (100 ml). The combined organic phases were washed with water (100 ml), with a saturated aqueous solution of NaCl (100 ml), dried (MgSO4), and concentrated. FC (90 g SiO2, hexane/MTBE 95:5) of the crude product (2.05 g) gave methyl 7-methylspiro[4.5]dec-6-ene-6-carboxylate (1.16 g, 42% three-step overall yield). Boiling point: 105° C. (0.08 mbar).

Provenance & Evidence