HCID 14136727, compound → HCID 86691656, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of (methyl)triphenylphosphonium bromide (49.9 mmol, 18.2 g) in dry tetrahydrofuran (THF) (100 mL) at −78° C. was added n-butyllithium (46.5 mmol, 18.6 mL of 2.5 M solution in hexanes). The mixture was stirred for 30 min at −78° C. To this mixture was added spiro[bicyclo[2.2.1]heptane-2,1′-cyclobutan]-3-one (5.00 g, 33.3 mmol). The resulting mixture was stirred at ambient temperature for 20 h. Hexanes (300 mL) were added, and the mixture was filtered. The filtrate was concentrated, and the residue was purified on an 80 g silica gel column, eluting with hexanes, to obtain 3-methylenespiro[bicyclo[2.2.1]heptane-2,1′-cyclobutane] (Compound III in Scheme 1) (3.7 g, 75%) as oil. 1H NMR (CDCl3, 400 MHz); δ 4.82 (s, 2H), 2.63 (bra, 1H), 2.22 (bra, 1H), 2.05-1.78 (m, 6H), 1.63-1.52 (m. 1H), 1.48-1.34 (m, 3H), 1.21-1.12 (m, 2H).

Provenance & Evidence