791531-41-4Relevant articles and documents
REDUCTIVE TRANSFORMATION OF A HYDROXYIODOKETONE OF 8-AZABICYCLOOCTANE INTO 7-AZABICYCLOHEPTANE WITH LITHIUM ALUMINIUM HYDRIDE
Sarel, Shalom,Dykman, Edmund
, p. 719 - 734 (2007/10/02)
1α,4β-Diodo-2α-acetoxytropan-3-one (2) and 1α-iodo-2α-acetoxytropan-3-one (3), which comprise 64percent of products emerging from the lead tetraacetate oxidation of tropan-3α-ol in presence of iodine, were subjected to lithium aluminium hydride reduction.The expected 2.3-dihydroxytropane was not obtained.Instead, a diol which was not prone to periodate oxidation, containing one primary and one secondary alkoholic groups was obtained.It was assigned the 1-hydroxymethyl-2α-hydroxy-7-methyl-7-azabicycloheptane structure (8), on the basis of spectroscopic evidences (ir, nmr and mass spectrometry) and some chemical transformations heptane (12)>.The reaction is understood as an initial β-elimination process, triggered by the delivery of hydride ion to the carbonyl function in the sequence 3 21 22, yielding a highly reactive enolate aldehyde (22) which is prone to an immediate internal aldol condensation (22) (23) (24), affording the observed diol (8) on further reduction of the a aldehydic group by LiALH4.The reductive deiodination of (3) into 2α-acetoxytropine (2b) or into 2α-hydroxytropan-3-one (25) was smoothly achieved by means of hydrogenation over Raney Nickel on mild basic conditions.
