Diastereoselective alkylation of carbanions derived from 1,3-oxathianes
摘要:
Carbanions derived from 4-substituted-1,3-oxathiolane and oxathiane were studied. The magnesium anion of 2-phenyl-4-t-butyldiphenylsilyloxy-1,3-oxathiane reacts with benzaldehyde to give the benzhydrol adduct in a seven to one ratio of diastereoisomers. It was also found that solvent had an effect on site of metalation and in ether 2-phenyl-4-dimethylamino-1,3-oxathiane reacts with s-butylithium to give ortho metalation. The resulting anion reacts with benzaldehyde to give a 4:1 ratio of diastereoisomers.
Diastereoselective alkylation of carbanions derived from 1,3-oxathianes
摘要:
Carbanions derived from 4-substituted-1,3-oxathiolane and oxathiane were studied. The magnesium anion of 2-phenyl-4-t-butyldiphenylsilyloxy-1,3-oxathiane reacts with benzaldehyde to give the benzhydrol adduct in a seven to one ratio of diastereoisomers. It was also found that solvent had an effect on site of metalation and in ether 2-phenyl-4-dimethylamino-1,3-oxathiane reacts with s-butylithium to give ortho metalation. The resulting anion reacts with benzaldehyde to give a 4:1 ratio of diastereoisomers.