A highly efficient synthesis of the keyintermediate 2 of 1β-methylcarbapenems was accomplished in 10 steps and 30% overall yield starting from commercially available ()-methyl 3-hydroxy-2-methylpropionate. The explored synthetic scheme features the addition reaction of diketene with a chiral imine as a key diastereoselective step.
[EN] 1'-METHYL-BETA-LACTAM COMPOUNDS AND THEIR PRODUCTION
申请人:SUMITOMO PHARMACEUTICALS COMPANY, LIMITED
公开号:WO1988001619A1
公开(公告)日:1988-03-10
(EN) A 1'-methyl-beta-lactam compound of formula (I), wherein R1 is an optionally substituted diarylmethyl group or an optionally substituted aryl group and R2 is a protective group for hydroxyl, which is useful as an intermediate in the synthesis of antimicrobial agents.(FR) Composé de 1'-méthyl-bêta-lactame de formule (I), dans laquelle R1 est un groupe diarylméthyl éventuellement substitué ou un groupe aryle éventuellement substitué et R2 est un groupe protecteur de l'hydroxyle. Ce composé est utile en tant que produit intermédiaire dans la synthèse d'agents antimicrobiens.
A novel and efficient synthesis of the key intermediate of 1β-methylcarbapenem antibiotics employing [ 2+2 ]-cycloaddition reaction of diketene with a chiral imine
steps and 30 % overall yield. Thus, (S)-3-benzyloxy-2-methylpropanal readily obtainable from (S)-5, was condensed with di-p-anisylmethylamine to afford the chiral imine. The [2+2]-cycloaddition reaction of diketene with the imine was found to proceed in a highly diastereoselective manner, giving the desired 3,4-trans-3-acetyl-β-lactam (max. diastereoselectivity 11-15:1). This was readily elaborated to