%0 Generic
%A Lan, Ping
%A Banwell, Martin G.
%A Willis, Anthony C.
%D 2019
%T Application of Electrocyclic
Ring-Opening and Desymmetrizing
Nucleophilic Trappings of meso-6,6-Dibromobicyclo[3.1.0]hexanes
to Total Syntheses of Crinine and Haemanthamine Alkaloids
%U https://acs.figshare.com/articles/dataset/Application_of_Electrocyclic_Ring-Opening_and_Desymmetrizing_Nucleophilic_Trappings_of_i_meso_i_-6_6-Dibromobicyclo_3_1_0_hexanes_to_Total_Syntheses_of_Crinine_and_Haemanthamine_Alkaloids/7794164
%R 10.1021/acs.joc.9b00018.s005
%2 https://ndownloader.figshare.com/files/14505140
%K alkaloids
%K application
%K ent
%K mixture
%K -2-bromo
%K Electrocyclic Ring-Opening
%K pretazettine
%K Total Syntheses
%K Haemanthamine Alkaloids
%K Suzuki
%K diastereoisomeric
%K hydroxyvattitine
%K Desymmetrizing Nucleophilic Trappings
%K Variations
%K chiral
%K chromatographically
%K presence
%K Crinine
%K tazettine
%K apohaemanthamine
%K 1-
%K C 2
%K cross-coupling
%K haemanthamine
%K dibromobicyclo
%K hamayne
%K cyclization
%K Pictet
%K nonracemic
%K electrocyclic ring-opening
%K bulbispermine
%K crinane
%K synthese
%K meso
%K 13 steps
%K Dibromobicyclo
%X The
thermally induced electrocyclic ring-opening of C2-symmetric
(meso) 6,6-dibromobicyclo[3.1.0]hexanes
such as 10 in the presence of the chiral, nonracemic
1°-amine 28 afforded a ca. 1:1 mixture of the diastereoisomeric
and chromatographically separable 1-amino-2-bromo-2-cyclohexenes 37 (42%) and 38 (45%). Each of these was elaborated
over 13 steps, including Suzuki–Miyaura cross-coupling, radical
cyclization, and Pictet–Spengler reactions, into (−)-
or (+)-crinane (1 or ent-1, respectively). Variations on these protocols were applied to the
total syntheses of (+)- and (−)-11-hydroxyvattitine [(+)- and
(−)-3], (+)- and (−)-bulbispermine [(+)-
and (−)-4], (+)- and (−)-haemanthamine
[(+)- and (−)-5], (+)- and (−)-pretazettine
[(+)- and (−)-6], and (+)- and (−)-tazettine
[(+)- and (−)-7] as well as (±)-hamayne [(±)-8] and (±)-apohaemanthamine [(±)-9].
A number of these alkaloids were synthesized for the first time.
%I ACS Publications