Synthesis and highly diastereoselective alkylation of chiral N-[(S,S)-3,5-bis(1-methoxyethyl)-1,2,4-triazol-4-yl]arylimines

Abstract

(S,S)-4-Amino-3,5-bis(1-hydroxyethyl)-1,2,4-triazole 2 (SAT) (from (S)-lactic acid and hydrazine hydrate) reacted with substituted benzaldehydes 6 to afford N-[(S,S)-3,5-bis(1-hydroxyethyl)-1,2,4-triazol-4-yl]arylimines 3 in excellent yield. Protection of the hydroxyl groups in compounds 3 was accomplished using methyl tosylate under mild conditions to give N-[(S,S)-3,5-bis(1-methoxyethyl)-1,2,4-triazol-4-yl]arylimines 4 in very high yield. Subsequent reactions of 4 with Grignard reagents afforded compounds 5 with good to excellent diastereoselectivities in good yield. Copyright © 1996 Elsevier Science Ltd.