87001-74-9Relevant academic research and scientific papers
ELIMINATION REACTION OF ANGULAR HYDROXYMETHYL GROUPS OF 20(29)-LUPENE DERIVATIVES
Vystrcil, Alois,Krecek, Vaclav,Budesinsky, Milos
, p. 1499 - 1507 (2007/10/02)
Solvolysis of 28-p-toluenesulfonyloxy-20(29)-lupene derivatives IV-VII proceeds with isomerization of the isopropenyl side chain to the isopropylidene chain and expansion of the ring E to a six-membered ring, containing trisubstituted double bond; for "anhydrobetulin" and its derivatives formulae VIII-XI with homoconjugated double bonds are suggested.Formation of a conjugated diene system is hindered by steric interactions of the isopropylidene chain with the ring C (with C(12)).Only the trisubstituted double bond in the dienes VIII and X undergoes catalytic reduction, the hydrogen approaching from the α-side (XII-XVI) as demonstrated by the Cotton effect of trinorketone XXI and its 20,20-dibromo derivative XXIII.
