Diastereoselective .alpha.-Alkylation of 2-Acyl-3-phenyl-l-menthopyrazoles
摘要:
N-Acylpyrazoles were alpha-alkylated in good yields by the treatment with alkyl halides after metalation with LDA or LiHMDS, In the case of chiral N-acylpyrazoles, e.g., 2-acyl-3-phenyl-l-menthopyrazoles (4), the alpha-alkylation was highly diastereoselective. The subsequent alpha-alkylation products could be converted into esters in good yield in the presence of BF3.OEt(2) without the loss of the optical purity.
Diastereoselective .alpha.-Alkylation of 2-Acyl-3-phenyl-l-menthopyrazoles
摘要:
N-Acylpyrazoles were alpha-alkylated in good yields by the treatment with alkyl halides after metalation with LDA or LiHMDS, In the case of chiral N-acylpyrazoles, e.g., 2-acyl-3-phenyl-l-menthopyrazoles (4), the alpha-alkylation was highly diastereoselective. The subsequent alpha-alkylation products could be converted into esters in good yield in the presence of BF3.OEt(2) without the loss of the optical purity.