Synthesis of α-fluoro-β-hydroxy alkylsulfanyl esters via a nucleophilic fluorination of sulfides
摘要:
By halogen-exchange reaction using NEt3-3HF as fluoride source, methyl 2-fluoro-2-alkylsulfanyl acetate 3a-d could be obtained in good yields. Their ester enolates reacted with aromatic or aliphatic aldehydes, to lead to methyl alpha-alkylsulfanyl-alpha-fluoro-beta-hydroxy esters 4-8. By using benzaldehyde as electrophile, the retro-aldol reaction could be favorised by a temperature effect. The selective formation of the syn or the anti diastereoisomers has been controled. (C) 1998 Elsevier Science Ltd. All rights reserved.