Hydrochloric Acid → HCID 131732744, compound

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl 7-methyl-9-oxospiro[4.5]dec-7-ene-6-carboxylate (6.4 g, 27.3 mmol) in methanol (120 ml) was treated with anhydrous cerium trichloride (6.72 g, 27.3 mmol). The resulting mixture was stirred for 45 min., cooled to 0° C., and added within 40 min. to a mixture of sodium borohydride (0.75 g, 96%, 19.1 mmol) in methanol (60 ml) at 0° C. The resulting mixture was stirred for 2 h at 20° C., cooled to 0° C., treated with sodium borohydride (0.75 g, 96%, 19.1 mmol), stirred for 3 h at 20° C., cooled to 0° C., poured into 2N aqueous HCl and ice, and extracted three times with MTBE (200 ml). The combined organic phases were washed three times with a saturated aqueous solution of NaCl, dried (MgSO4) and concentrated. FC (SiO2, hexane/MTBE 3:1) of the crude product (7.6 g, cis/trans 19:81) gave cis-ethyl 9-hydroxy-7-methylspiro[4.5]dec-7-ene-6-carboxylate (0.82 g 13%), 29:71 cis-/trans-ethyl 9-hydroxy-7-methylspiro[4.5]dec-7-ene-6-carboxylate (0.71 g, 11%), and trans-ethyl 9-hydroxy-7-methylspiro[4.5]dec-7-ene-6-carboxylate (3.52 g, 54%).

Provenance & Evidence