synthase gave rise to specifically deuteriated exomethylene cepham (6) and α-hydroxymethyl penam (7) products via the concomitant operation of stereospecific desaturative and hydroxylative ring closure pathways. The stereochemistries observed are in accord with competing ‘Ene’ and [2π+ 2π]cycloaddition of the proposed iron-oxo intermediate.
的变换大号- α -aminoadipoyl-大号-cysteinyl- d - (ż) - [4- 2 H] isodehydrovaline(5B)和大号- α -aminoadipoyl-大号-cysteinyl- d - (ë) - [4- 2 ħ异戊西林N合酶产生的]异氢缬
氨酸(5c)产生了专门的
氘化的exomethyl cepham(6)和α-羟甲基penam(7)产物。立体特异性去饱和和羟基化闭环途径的伴随操作。所观察到的立体
化学符合提议的
铁-氧代中间体的竞争性“ Ene”和[2π+2π]环加成。