| 摘要 |
PURPOSE:To obtain the subject compound by deesterification and decarboxylation, starting from, as raw material, a 4-(1,1-dialkoxycarbonylalkyl) azetidin-2-one derivative having such a structure that a malonic acid derivative is bonded to the 4-site of azetidin-2-one skeleton. CONSTITUTION:The objective compound of formula II can be obtained by deesterification and decarboxylation using, as raw material, a 4-(1,1- dialkoxycarbonylalkyl)azetidin-2-one derivative of formula I (R<1> and R<2> are each alkyl, alkenyl or aralkyl; R<3> is alkyl; R<4> is H or protecting group for OH; R<5> is H or protecting group for amino) followed by, in case a protecting group is present at the amino group, deprotection. For example, one of the objective compounds (i.e., of formula IV) can be obtained by deesterification and decarboxylation of a compound of formula III. The compound of the formula II is useful as an intermediate for synthesizing various kinds of 1beta- alkylcarbapenem antibacterial agents. |
