Beilstein J. Org. Chem.2017,13, 2214–2234, doi:10.3762/bjoc.13.220
used as a key stage to construct an important C(7)–C(8) connection in the total synthesis of (+/−)-myrioneurinol (Scheme 15) [34][35]. α-Chloroxime TBS ether 43 (prepared in 10 steps from δ-valerolactam) reacted with a dimethyl malonate anion under Denmark’s conditions via intermediate NSA9 to give the
Beilstein J. Org. Chem.2013,9, 1613–1619, doi:10.3762/bjoc.9.184
chemical transformation which typically eliminates the requirements for any conventional work-up or purification of the reaction stream.
Keywords: chloroxime; dipolar cycloaddition; flow chemistry; flow synthesis; immobilised reagents; isothiocyanate; nitrile oxide; Introduction
Flow based chemical
weak base and a functionalised thiourea) placed as a 1:1-mixture within a single glass reactor cartridge (Scheme 2). The immobilised base affects the in situ formation of the reactive nitrile oxide from the chloroxime which is immediately captured by the local tethered thiocarbonyl dipolarophile
for trapping even the small quantities of polar impurities within the matrix thus allowing for the isolation of the desired isothiocyanate product in high purity after only simple solvent removal.
Results and Discussion
Initially a set of batch experiments was performed using (4-bromophenyl)chloroxime