The final stages in the total synthesis of vitamin B12 are reported. It was particularly appropriate, I think, and most pleasant for us this morning to see the splendid film provided by our Russian friends, in which the very successful Symposium at Riga was enshrined for posterity. Appropriate in the sense, from my own point of view, that I did report there at Riga, on the progress we had made up until that time, namely, the summer of 1970, in the joint programme, which had as one of its objectives the synthesis of vitamin —a programme carried out collaboratively by myself and Professor Eschenmoser at the Eidgenossische Technische Hochschule in Zurich, with of course our colleagues in Cambridge and Zurich. We have worked very closely and intimately together in this project, and it is an achievement—such as it may be—of the two groups together. So, anything I say this afternoon—or what is left of the morning and this afternoon—I am saying for Professor Eschenmoser and his colleagues as well as for myself and my colleagues in Cambridge.

中文翻译：

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维生素B12的全合成

报告了维生素 B12 全合成的最后阶段。我认为，今天早上看到我们的俄罗斯朋友提供的精彩电影是特别合适的，也是最令人愉快的，在里加非常成功的研讨会被供后人纪念。从我个人的观点来看，我确实在里加报告了我们在 1970 年夏天之前在联合计划中取得的进展，该联合计划的目标之一是适当的维生素的合成——一个由我和苏黎世 Eidgenossische Technische Hochschule 的 Eschenmoser 教授合作开展的项目，当然还有我们在剑桥和苏黎世的同事。我们在这个项目中密切合作，这是两个团队共同取得的成就——可能是这样。所以，