The stereochemistry of intermediates in the total synthesis of d1-aspidospermine

✍ Scribed by Yoshio Ban; Ikuo Iijima; Ichizo Inoue; Masao Akagi; Takeshi Oishi

• Publisher: Elsevier Science
• Year: 1969
• Tongue: French
• Weight: 265 KB
• Volume: 10
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)88087-4

✦ Synopsis

In the preceding papers (l), we reported that a-7-keto-decahydroquinoline was synthesized by the method of Grob (2) and derived to I in a similar way for synthesis of dl-aspldospermine(V) (3,4). The structure of the compound(I) was proved to be Ia, whose n.m.r. spectrum was well similar to that of our compound(II1) (3), but not to Stork's one (4). We therefore suspected the previous stereochwical assignments for the intermediates in the syntheses of dl-aspidospermine (3,4,5), in which III-A and IV-A were given by Stork to their caapounds(A/B: trans), while 111~ and IVc were preferred by us for our intermediates(A/B: cis), and Kuehne adopted IVd and IVf for their isomeric ketones(IV) on direct comparison with Stork's and our substances (5). Based upon the following experiments, we propose the new assigwent that A/B ring juncture in our compounds(II1 and IV) should be trans as they are demonstrated by the formulas, IIIa(A/C: a) and IV-A(A/C: e).