5- Hydroxy-4-methyl -3- hexanone

Show how to prepare 5-hydroxy-4-methyl-3-hexanone using a crossed aldol reaction. 

Additional aldehydes and ketones were also included in the U.S. Nationwide Occurrence Study dimethylglyoxal (2,3-butanedione), cyanoformaldehyde, 2-butanone (methyl ethyl ketone), trans-2-hexanal, 5-keto-l-hexanal, and 6-hydroxy-2-hexanone [11, 13]. Dimethylglyoxal was the most consistently detected of these carbonyl compounds (up to 3.5 pg/L) and was found at higher levels in plants using ozone. Maximum levels of 0.3, 5.0, and 0.7 pg/L were observed for cyanoformaldehyde, 2-butanone, and trans-2-hexenal, respectively 6-hydroxy-2-hexanone and 5-keto-1 -hexanal were only detected in early stages of treatment, and not in finished waters. 

Methyl ethyl ketone (2-butanone) 6-Hydroxy-2-hexanone Dimethylglyoxal (2,3-butanedione)... 

Moreover, a reaction of the Mannich type has been observed with heterocyclic enamines, e.g. in the treatment of 1,2-dimethyl-A2-piperideine with formaldehyde as described by Lipp and Widn-mann.350 In the condensation, the ring-opened form, viz. 1-methyl-amino-5-hexanone, is presumably involved. Recrystallization of the intermediate Y-hydroxy methyl derivative then gives the final 1-methyl-3-acetylpiperidine (121). 

Suppose a starting material A contains both a ketone and an ester, and it is necessary to selectively reduce the ester to an alcohol (6-hydroxy-2-hexanone), leaving the ketone untouched. Such a selective reduction is not possible in one step. Because ketones are more readily reduced, methyl 5-hydroxyhexanoate is formed instead. 

Japanese cedar (Cryptomeria japonka) Anaj lyptus subjiisciatus Methyl Phenyl Acetate (R)-3-hydroxy-2-hexanone, (R)-3-hydroxy-2-octanone [222]... 

Hydroxymethylation of ketones.1 A ketone can be converted into the a-hydroxy-methyl derivative in two steps acylation with ethyl formate, followed by aluminum hydride reduction. The sequence is illustrated for the conversion of 4-/er/-butylcyclo-hexanone (1) into 2-hydroxymethyl-4-te rt-butylcyclohexanone (3). 

The metabolites of n-hexane injected in guinea pigs were reported as 2,5- hexane-dione and 5-hydroxy-2-hexanone, which are also metabolites of methyl butyl ketone (DiVincenzo et al. 1976). Thus methyl butyl ketone and n- hexane should have similar toxicities. The neurotoxic metabolite, 2,5-hexanedione, however, is produced considerably less in n-hexane. However, in the case of hexane, the neurotoxic metabolite 2,5-hexanedione is produced to a much lesser extent. Continuous exposure to 250 ppm n-hexane produced neurotoxic effects in... 

Syn 3-(EthyltHloniethyl)-4-hydroxy-6-pt)enyl-2-hexanone (4) and anti (5) To ethanethiol (10 0 mg 0 17 mmol) in THF (2 mL) was added 1 54 M n butyltittnum m hexane (0 11 mL) at 0 C under Ar Stannous triflate (69 0 mg 017 nvnol) was added and alter 20 mm the mocture was cooled to 4S°C Methyl vinyl Ketone 1 (118 mg 1 98 mmol) m THF (1 5 mL) was added followed by 3 phenyiptopanal 3 350 mg 2 61 mmol) m THF (1 S mL) Alter 12 h aq cilnc acid was added and the organic material extracted with OHjClj The resxlue after evaporation was dissolved in MeOH and treated with citric acxt After 30 min stimng, the mixture was quenched with pH 7 phosphate buffer extracted with CH2CI2, the solvent evaporated and the residue chromatographed to afford 336 mg ot 4 (75%), syn anti (90 10)... 

ACETATE AND ALDEHYDES OR KETONES ETHYL 1-HYDROXYCYCLO-HEXYLACETATE, 53, 66 2- (Hydroxymethylene)cyclohexanone with p-toluenesulfonyl azide to give 2-diazocyclo-hexanone, 51, 86 y-HYDROXY-ct, (3-UNSATURATED ALDEHYDES VIA 1,3-BIS(METHYL-THIO) ALLYLLITHIUM trans-4-HYDROXY-2-HEXENAL, 54, 19... 

We now turn to the remaining two hydroxylamines that are N-hydroxylated derivatives of 2,2,6,6-tetramethyl-4-piperidone and -4-piperidinol. The enthalpies of formation of some simple 4-piperidones and their corresponding 4-piperidinols have recently been determined. The values of gaseous N-methyl-4-piperidone and Af-methyl-4-piperidinol are —160.7 1.7 and —226.8 1.8 kJmol (also see Reference 18). The difference between these contemporary values is — 66.1 2.5 kJmol while for the hydroxylated and methylated counterpart species the difference is —47.0 4.8 kJmoH. For comparison, the formal enthalpy of reduction of 3-hexanone to 3-hexanol is ca —54 kJmoH. As has been discussed earlier, reduction enthalpies are not necessarily constant . Relatedly, reaction 8 that exchanges N-methyl and N-hydroxy and parent and tetramethylpiperidines is endothermic by 19.1 5.4 kJmol . The deviation from thermoneutrality is more... 

Hexanone, 2-heptanone, 2-octanone, 2-nonanone, 6-methyl-5-hepten-2-one, fenchone, carvone, acetophenone, 2-hydroxy-4,6-dimethoxy-5-methylacetophenone... 

C7H1402 2-hydroxy-2-methyl-3-hexanone 18905-91-4 440.15 38.165 1,2 12026 C7H15N cis-2-methylcyclohexyl amine 2164-19-4 426.65 40.340 1,2... 

C7H1402 5-hydroxy-2-methyl-3-hexanone 59357-07-2 427.81 36.993 2 12027 C7H15N trans-2-methylcyclohexylamine 931-10-2 423.15 39.108 1,2... 

Figure 5.2.11. Cellulose pyrolysate obtained at 59(P C and separated on a methyl silicone with 5% phenyl silicone type column. 1 acetic anhydride, 2 pentanal, 3 2-hydroxybutanedialdehyde, 4 1,4-dioxadiene, 5 tetrahydro-2-furanmethanol, 6 2-(hydroxymethyl)-furan, 7 3-methyl-2-hexanone, 8 2-methoxy-2,3-dihydrofuran, 9 2(5H)-furanone, 10 1-acetyloxypropan-2-one, 11 hydroxycyclopentenone, 12 5-methylfurfural, 13 2,3-dihydro-5-methylfuran-2-one, 14 1-cyclopentylethanone, 15 2-hydroxy-3-methyl-2-cyclopenten-1-one, 16 3,5-dimethylcyclopentan-1,2-dione, 17 unknown, 18 3-ethyl-2,4(3H,5H)-furandione, 19 6-methyl-1,4-dioxaspiro[2,4]heptan-5-one, 20 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one, 21 1,4 3,6-dianhydro-a-D-glucopyranose, 22 5-(hydroxymethyl)-furfural, 23 4-cyclopenten-1,2,3-triol, 24 5-ethyl-3-hydroxy-4-methyl-tetrahydrofuran-2-one, 25 levoglucosan, 26 1,6-anhydro-p-D-glucofuranose.

Label all a- and fi-bonds for each functional group in (a) 4 hydroxy-5-methyl-2-hexanone, (b) 2-cyano-l-phenyl-l-propanoI, and (c) 2-methyl-6-pbenyl-3-hexanone. 

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