Improved procedures and intermediates for synthesizing 11-deoxyprostaglandins wherein trans-2,3-dicarbomethoxycyclopentanone is prepared by the novel kinetically-controlled cyclization of 1,2,4-tricarbomethoxybutane using a dispersion of sodium hydride in dry p-xylene. Selective alcoholysis of the 2-position carbomethoxy group with benzyl alcohol, followed by alkylation allows for a wide range of upper side chains to be introduced at the 2-position of the cyclopentanone ring. The unwanted carbobenzyloxy group at the 2-position can then be removed easily by controlled hydrogenolysis followed by decarboxylation. This procedure allows for simultaneous epimerization of the 2-position side chain to the desired trans-configuration, relative to the carbomethoxy group in the 3-position, as well as for reduction of the 2-hexynyl moiety of the side chain to the desired cis-olefinic group of the E.sub.2 -type 11-deoxyprostaglandins, or through total reduction to the alkane upper side chain of E.sub.1 -type prostaglandin analogs. Modification thereafter of the carbonyl group at the 3-position of the cyclopentanone ring by a variety of reagents allows introduction of the lower side chain present in the prostaglandins themselves or a variety of other side chains derived from the 3-carboxy-, 3-hydroxymethyl- or 3-aldehyde-substituted cyclopentanone ring. From the latter, 11-deoxyprostaglandins can be prepared by known procedures.
改进的程序和中间体用于合成11-去氧
前列腺素,其中通过使用干燥的p-二
甲苯中的氢化
钠分散体,利用新颖的动力学控制环化反应制备反-2,3-二羧甲氧基
环戊酮。使用
苄醇选择性醇解2-位置的羧甲氧基基团,然后进行烷基化,可在
环戊酮环的2-位置引入广泛的上侧链。然后可以通过控制的氢解和脱羧作用轻松地去除2-位置的不需要的羧苄氧基基团。该程序允许将2-位置侧链同时使其与3-位置的羧甲氧基基团呈现所需的反式构型,以及将侧链的
2-己炔基团还原为所需的E.sub.2型顺式烯基基团,或通过完全还原为E.sub.1型
前列腺素类似物的烷基上侧链。然后,通过各种试剂修改
环戊酮环的3-位置的羰基基团,可以引入
前列腺素本身或从3-羧基,3-羟甲基或3-醛基取代的
环戊酮环中衍生的各种侧链。从后者,可以通过已知的程序制备11-去氧
前列腺素。