6630-39-3Relevant academic research and scientific papers
Claisen Orthoester Rearrangement in the Direct Preparation of Z-Isositsirikine and Z-Geissoschizine Derivatives Possessing the Right Oxidation State at C-17
Lounasmaa, Mauri,Hanhinen, Pirjo,Jokela, Reija
, p. 8623 - 8648 (2007/10/02)
The Claisen orthoester rearrangement utilizing allylic alcohol 1 (or 2) and trimethyl 3-methoxyorthopropionate 13a leads to Z-isositsirikine derivatives 21a-22a (or 23a-24a) possessing one RO-function at C-17.In the cases of trialkyl 3,3-dialkoxyorthopropionates , the intermediate ketene acetals 25a,b do not rearrange according to the Claisen mechanism to form compounds 26a,b and/or possessing two two RO-functions at C-17.Syntheses of the intermediate orthoesters, trimethyl 3-methoxyorthopropionate 13a, trimethyl 3,3-dimethoxyorthopropionate 14a, trimethyl trans-3-methoxyorthoacrylate 20c, and triethyl 3,3-diethoxyorthopropionate 14b are described.
