Glyoxylate, n-butyl

VI.37. OXIDATION WITH LEAD TETRA-ACETATE n-BUTYL GLYOXYLATE... 

Store the n-butyl glyoxylate under nitrogen it undergoes autoxidation in air. The product decomposes on boiling (159-161°) at atmospheric pressure. 

Reaction of o-phenylenediamine and n-butyl glyoxylate gives quinoxalin-2-onc in excellent yield with 4-nitro-o-phcnylcncdiaminc (5) a mixture of 6- and 7-nitro-quinoxaIin-2-ones, (6) and (7), is obtained. ... 

Butylfluorene, 39, 45 ferf-Butyl glutarate, 34, 28 n-Butyl glyoxylate, 35,18 lerl-BvTYl. HYPOCHLORITE, 32, 20 K-Butyl iodide, 30, 34... 

An interesting application of lead tetra acetate is to the preparation of the otherwise difficulty-accessible n-butyl glyoxylate (II) by oxidation of dt-n-butyl d-tartrate (I) ... 

To a mixture of 1-methoxy-l,3-butadiene (1 55.3 g, 0.66 mol) [43] and n-butyl glyoxylate (86.0 g, 0.66mol) [44], 0.1 g hydroquinone was added and the solution was refluxed at 100°C for 6 h under argon. Distillation at 88°-90°C/0.5 tonr gave 2 (R = Bu) (91.6 g, 65%) as a pale-yellow liquid with a faint odor. By gas chromatography this product is a mixture of cis and trans (ca. 7 3) isomers. Treatment of the isomer mixture in dichloro-methane solution with p-toluenesulfonic acid or zinc chloride for 2 h leads to an almost pure trans-isomer (ca. 95%). 

The experimental study was carried out with two different imines a standard one, n-hesanaldimine, and an electron-poor one, n-butyl glyoxylate imine. The Scheme 34 shows that the formation of the (3-lactam occurred only when the glyoxylate imime and BF3-Et20 reacted with (trimethylsilyl)ketene. 

Mikami et al. studied the Diels-Alder reaction between a-methylstyrene and n-butyl glyoxylate catalyzed by a titanium binolate catalyst.76-78 Addition of 0.5 equivalents of (Zf)-BINOL to 1 equivalent of the racemic catalyst accelerated the reaction and gave the product with 89.8% ee (Scheme 20). Enantiopure catalyst derived solely from (/ )-BINOL gave the product with 94.5% ee. Here the amplification originates from the creation of a new chiral complex 9 of higher efficiency (rate and enantioselectivity) with respect to each enantiomer of the original racemic catalyst. 

Preparation. A solution of n-butyl glyoxylate and N-suIlinyl-p-toluenesul-fonamide in benzene is refluxed and a solution of aluminum chloride in nitrobenzene is added slowly."... 

More recently, Hosomi et al. reported some regioselective cycloadditions of silyl-substituted 1,3-dienes with n-butyl glyoxylate to afford dihy-dropyrans in good yields (Scheme 4-1). As in the examples cited above, products in the last two cases were stereoisomer mixtures due to ready epimerization at C-2. -Butyl glyoxylate also reacts smoothly with 1,3-cyclohexadiene under thermal conditions, affording a 9 1 mixture of the endo and exo bicyclic adducts, respectively [Eq. (5)]. ... 

Stereochemistry of Cydoadditions of Chiral Dienes with n-Butyl Glyoxylate"... 

Quinoxalin-2-one (3) is readily prepared by the condensation of o-phenylenediamine and n-butyl glyoxylate (2). The latter compound is conveniently obtained from sodium periodate oxidation of n-butyl tartrate... 

Condensation of the diaminoisothiazole 50 with n-butyl glyoxylate is reported to give the fused pyrazine 51. No comments were made about possible formation of the 5-hydroxy isomer. " Presumably the compound is more accurately described as the oxo tautomer 52. 

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