Synthesis of Substituted-(l)-Tryptophanols from an Enantiomerically Pure Aziridine-2-methanol

Abstract

Enantiomerically pure (l)-tryptophanol (5) was synthesized from 4(R)-iodomethyl-2-oxazolidinone (2) and indolylmagnesium bromide in three steps (52% overall yield). Using this procedure, we also prepared various tryptophanols with substituent(s) on the indole ring. Furthermore, optically active 4(R)-iodomethyl-2-oxazolidinone was readily prepared from an enantiomerically pure aziridine-2(S)-methanol in high yield. [reaction: see text]

Regioselective and Stereospecific Synthesis of Enantiopure 1,3-Oxazolidin-2-ones by Intramolecular Ring Opening of 2-(Boc-aminomethyl)aziridines. Preparation of the Antibiotic Linezolid

“…In fact, ring expansions of optically active aziridines have been employed to prepare optically active 1,3-oxazolidin-2-ones. For instance, Korean researchers have used processes of this type in two main stereoselective ways: (a) cyclization at the N and O atoms of aziridines 3 using either iodotrimethylsilane and 1,1′-carbonyldiimidazole or sodium hydride and phosgene and (b) activation of the nitrogen atom of aziridines 4 as a carbamate by reaction with methyl chloroformate, with subsequent ring opening by the chloride anion and ring closure through the carbamate carbonyl . The latter option is close to the ring expansion of activated N -Boc aziridines 5 to 1,3-oxazolidin-2-ones, which has been reported to occur stereoselectively with lithium halides in the presence of Amberlyst 15 and also with the aid of Lewis acids.…”

N-(1-Phenylethyl)aziridine-2-carboxylate esters in the synthesis of biologically relevant compounds

“…By functionalization at C3: In the presence of carbonyldiimidazole (CDI) and iodotrimethylsilane the aziridine alcohol (2 S ,1' S )- 7 was transformed into the 4-(iodomethyl)oxazolidin-2-one (4 R ,1' S )- 39 via a regioselective opening with iodide and cyclization (Scheme 12) [50]. As expected alkylation of the indole ring with (4 R ,1' S )- 39 occurred at C3 to give (4 S ,1' S )- 40 which was deprotected in two steps (Birch reduction and alkaline hydrolysis) to provide ʟ-tryptophanol (( S )- 41 ).…”

Five-membered oxaza heterocyclic compounds on the basis of epoxides and aziridines

“…The best yield (98%) and stereoselectivity were Scheme 73. Pyun et al [158] described the synthesis and transformations of 1,3-oxazolidin-2-one 129 [158]. The formation of 129 is preceded by regioselective cleavage of the C 3 -N bond by the action of iodotrimethylsilane, and subsequent heterocyclization involves N,N′-carbonyldiimidazole (Scheme 77).…”