反应详情

Compound 14 (20.0 g, 64 mmole) in methylene chloride (400 ml) was added to a solution of lithium dimethyl cuprate (165 mmole) prepared in ether (800 ml) with cooling in an ice-salt bath under an argon atmosphere. The mixture was stirred at this temperature for 1 hour after which it was poured into saturated NH4Cl solution (1 liter). After the addition of concentrated NH4OH to pH~12 and stirring for 30 minutes, the organic phase was separated and washed twice with dilute NH4OH. The aqueous phase was extracted with additional methylene chloride and the combined organic phases dried and evaporated to give a quantitative yield of 16b as a thick syrup, NMR: δ 6.63, s, 2H (aromatic); 4.25, d, 1H (H-5α, J=13H); 3.80 (CH3O--); 2.43 (CH3N--); 1.08; unsymmetrical t, 3H (8β-CH3, J=6H); 0.90, symmetrical d, 3H (7α-CH3, J=6H). A portion of this material was converted to the hydrochloride salt by dissolving the syrupy free base in ethanol and adding excess concentrated HCl. The solution was evaporated to dryness and the residue azeotroped with ethanol, 1:1 V/V ethanol:benzene, then benzene. The residue was crystallized from ethyl acetate to give 16b HCl, mp 259°-262°.

1. temperaturewith cooling in an ice-salt bath under an argon atmosphere
2. stirringstirring for 30 minutes
3. customthe organic phase was separated
4. washwashed twice with dilute NH4OH
5. extractionThe aqueous phase was extracted with additional methylene chloride
6. customthe combined organic phases dried
7. customevaporated