The atisane ? aconane conversion: stereospecific skeletal rearrangements during the pyrolysis of epimeric toluene-p-sulphonates

Abstract

A POSSIBLE biosynthetic relationship between the atisine to a 7-5 B/C ring system; (b) formation of the C-7 -+ C-20 and aconitine-lycoctonine groups of diterpene alkaloids bond by Mannich addition. The order of steps (a) and (b) was sug5ested independently by Valenta and Wiesnerl and might be reversed. A re-e~aluation~,~ of the mechanism by Cool:son and Trevett in 1956.2 In essence, both schemes which generates the well-known "pyro" compounds in the consist of the two steps depicted in (I) -+ (11) : (a) Wagner-aconitine series, suggests a modification of the original ;\leerwe in rearrangement of a C,, (loss of C-17 of atisine) Wiesner-Cookson hypothesis. -4ccording to this, the interintermediate (I) derivable from atisine, leading from a 6-6 mediate alkene (111) participates in a Prins-type addition

Rearrangements in the Diterpenoid Series. I. The Solvolysis of Methyl 15β-tosyloxy-13-isopropyl-17-noratis-13-en-18-oate

“…The ease with which the desired rearrangement (i.e., 14c +-16a) occurs in this case contrasts with that observed (4,5) in the case of derivatives of atisine itself. It appears, not unexpectedly (20), that the presence of the C,,-C,, unsaturation greatly facilitates the rearrangement.…”

A simple synthesis of protoadamantene and 2,4-dehydroadamantane

“…By J. BOYD and K. H. OVERTON* (Department of Chemistry, The University of Glasgow, Glasgow, W.2) Summavy 2-Adamantyl methanesulphonate has been converted by pyrolysis in 95% yield into a mixture (2 : 3) of protoadamantene (4) and 2, kdehydroadamantane (5) ; hydroboration of protoadamantene and oxidation afforded protoadamantan-4-and -5-ones (5 : 4).…”