Sodium hydride

Abstract

(A) A series of 3α-arylmethoxy-3β-arylnortropanes were synthesized by alkylation of the corresponding tertiary alcohols using NaH. (FIGURE) (B) The first synthesis of 1,3-oxaselenepane derivatives by the reaction of aryl isoselenocyanates with 4-bromobutanol in the presence of sodium hydride as a one-pot reaction was reported recently where the Z/E isomerism for the exocyclic carbon nitrogen double bond in the selenium heterocycles was observed for the first time. (FIGURE) (C) Despite their important physicochemical and therapeutic properties, until 2008 only two structures bearing 7-hexahydro-aza-indoles prototype nucleus were known in the literature.5 An effective route involves the reaction of enaminonitrile γ-lactams derived from Nalkyl-α-bromoacetamides and malononitrile in the presence of NaH with acryloyl chloride derivatives. (FIGURE) (D) A novel eight-membered polyhydroxylated salicylic acid lactone was prepared from 2,6-dihydroxybenzoic acid and sodium thio-D-glucose. The key step involved a NaH-promoted intramolecular lactonization in the presence of excess TMSCl which led to the isolation of the 'natural product like' lactone. (FIGURE) (E) In a one-pot procedure, diethyl N-arylphosphoramidates were treated with NaH to generate an anion in situ, which underwent an aza-Michael addition to Baylis-Hillman adducts followed by cyclization to afford the azetidine-3-carbonitriles/carboxylates. (FIGURE) (F) The treatment of morphinan with NaH and MsCl provided a very stable iminium salt possessing a propellane skeleton. The iminium ion is expected to be a key intermediate for the synthesis of novel opioid ligands. (FIGURE) (G) A novel and efficient aziridination of a-halo ketones with diethyl N-arylphosphoramidates affords diethyl N-aryl-N-(2-oxoalkyl)-phosphoramidates which undergo reductive cyclization with NaBH4 followed by NaH to give highly diastereoselective 1,2-disubstituted and 1,2,3-trisubstituted aziridines. © Georg Thieme Verlag Stuttgart - New York.