Synthesis of versatile chiral intermediates by enantioselective conjugate addition of alkenyl Grignard reagents to enamides deriving from (R)-(−)- or (S)-(+)-2-aminobutan-1-ol
作者:Eric Brown、Christelle Deroye、Joël Touet
DOI:10.1016/s0957-4166(98)00135-9
日期:1998.5
Conjugate addition of but-3-enylmagnesium bromide to the chiral crotonamide (R)-(+)- and (S)-(−)-3, followed by hydrolysis and oxidation, afforded enantiopure (R)-(+)- and (S)-(−)-3-methyladipic acids 8, respectively. Conjugate addition of vinylmagnesium chloride to the chiral crotonamide and cinnamamides (R)-(+)-3–5, followed by hydrolysis, gave the alkenoic acids (S)-12–14, respectively. Iodolactonization
在手性巴豆酰胺(R)-(+)-和(S)-(-)- 3上共加入溴3-丁基溴化镁,然后水解和氧化,得到对映纯(R)-(+)-和(S)-(-)- 3-甲基己二酸8。共轭加成的乙烯基氯化镁的手性巴豆酰胺和cinnamamides([R )- (+) - 3 - 5,接着进行水解,得到的链烯酸(小号) - 12 - 14,分别。后者的碘内酯化导致生成5-碘甲基内酯(+)- 15 – 17,将其借助于减少Ñ -Bu 3 SNH入反式二取代的5- methyllactones(+) - 19 - 21,分别。用LiMe 2 Cu或n- Bu 2 CuLi处理碘甲基内酯(+)- 16,得到了反式-5-烷基-4-苯基内酯(-)- 22或(+)- 23。