Formation of 3-[1'-(dimethylphenylsilyl)ethyl]azetidin-2-ones: stereocontrolled formal approach to (.+-.)-thienamycin and (.+-.)-.beta.-(hydroxyalkyl)aspartic acid derivatives
摘要:
Reaction between (+/-)-beta-(dimethylphenylsilyl)alkanoyl chlorides and imines of glyoxylic esters provided a route to (+/-)-cis-3-[1'-(dimethylphenylsilyl)ethyl]-4-alkoxycarbonyl beta-lactams, while addition of the Fleming's silylcuprate reagent to methyl crotonate and further enolate trapping by the above imines furnished the corresponding (+/-)-trans-3-[1'-(dimethylphenylsilyl)ethyl]-4-alkoxycarbonyl beta-lactams. These beta-lactams, upon appropriate chemical manipulations, provided a stereocontrolled route to (+/-)-thienamycin precursors and (+/-)-beta-(hydroxyalkyl)aspartic acid derivatives.
Formation of 3-[1'-(dimethylphenylsilyl)ethyl]azetidin-2-ones: stereocontrolled formal approach to (.+-.)-thienamycin and (.+-.)-.beta.-(hydroxyalkyl)aspartic acid derivatives
摘要:
Reaction between (+/-)-beta-(dimethylphenylsilyl)alkanoyl chlorides and imines of glyoxylic esters provided a route to (+/-)-cis-3-[1'-(dimethylphenylsilyl)ethyl]-4-alkoxycarbonyl beta-lactams, while addition of the Fleming's silylcuprate reagent to methyl crotonate and further enolate trapping by the above imines furnished the corresponding (+/-)-trans-3-[1'-(dimethylphenylsilyl)ethyl]-4-alkoxycarbonyl beta-lactams. These beta-lactams, upon appropriate chemical manipulations, provided a stereocontrolled route to (+/-)-thienamycin precursors and (+/-)-beta-(hydroxyalkyl)aspartic acid derivatives.