Tributylstannane → 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[b]pyran

Participants

Reaction Steps

In 40 ml of anhydrous toluene, is dissolved 1.20 g of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(1-phenoxythiocarbonyloxy-3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[b]pyran obtained in Example 39. Then, 0.66 g of 2,2'-azobisisobutyronitrile and 1.16 g of tri-n-butyltin hydride are added at room temperature and reacted at 100° C. for 30 minutes. After the reaction, the reaction mixture is directly purified by silica gel column chromatography using 1/1 mixture of ethyl acetate/n-hexane as a developing solvent. Thus, 0.83 g of 6-cyano-2,2-dimethyl-4-{1,2-dihydro-2-oxo-4-(3-t-butyldimethylsilyloxypropyl)-1-pyridinyl}-2H-benzo[b]pyran is obtained.

Provenance & Evidence