【摘要】 为寻找更有效的新头孢菌素衍生物,本文报道了具脒硫基侧链的头孢菌素酸（R）和（S）型亚砜的立体定向合成。（S）-型亚砜衍生物II-（S）系将化合物V直接用过酸氧化,再与各种取代硫脲缩合而得。若将7-ACA转化为Schiff碱再行氧化则可立体定向地合成（R）-型亚砜Ⅶ,继而水解,酰化得Ⅸ。最后与各种取代硫脲缩合可得（R）-亚砜衍生物Ⅱ-（R）。所得各中间体及产物的立体化学均经₁H核磁共振予以证实。更多还原

【Abstract】 In order to find more active new cephalosporins a series of R- and S-sulfoxides of 7-(N, N’-substituted amidinothioacetamido) cephalosporanic acid was synthesized stereospecifically. The S-form sulfoxides Ⅱ-S were Prepared by oxidation of intermediate V with hydrogen peroxide and acetic acid and then condensation with a Variety of substituted thiourea. The R-form sulfoxides Ⅱ-R were prepared by several steps. After conversion of 7-ACA Ⅲ into corresponding Schiff’s base the R-form sulfoxide of the Schiff’s base was formed by oxidation. The intermediate Ⅸ was obtained by hydrolysis and acylation. The dersired derivatives Ⅱ-R could be prepared by condensation conveniently with N, N’-substituted thiourea.The stereochemistry of new cephalosporanie acid derivatives and intermediates has been idendified by means of ~1H NMR.更多还原