3- Bromo-2-heptanone

A suspension of N-methyl-4-dimethylaminothiobenzamide in methanol containing 3-bromo-2-heptanone shaken 6 days at room temp. 5-n-butyl-3,4-dimethyl-2-(p-dimethylaminophenyl)-4-hydroxy-2-thiazolinium iodide (Y 78%) refluxed 20 min. with methanolic HCI 5- -butyl-2-(p-dimethylaminophenyl)-3,4-dimethyl-thiazolium iodide (Y 70%). F. e. s. R. S. Egan et al., J. Org. Chem. 33, 4422 (1968). 

B-Butyraldehyde, condensation with N-phenylhydroxylamine, 46, 96 -Butyric acid, reaction with iron powder to yield 4-heptanone, 47, 75 Butyric acid, 7-bromo-, ethyl ester, 46, 42... 

Heptane, 1-bromo-2-fluoro, 46,10 Heptanoic acid, 2-fluoro-, 46,37 2-Heptanone, 47, 89 4-Heptanone, 47, 75 Heptanoyl fluoride, 46, 6... 

N-alkylation of 189 with either l-bromo-2-tetrahydropyranyloxyheptane or l-bromo-2-heptanone was not suited for the further synthesis. 

Alkylation with l-bromo-2-tetrahydropyranyloxyheptane gave only low yields of 197. The alkylation with l-bromo-2-heptanone resulted in formation of the tricyclic compounds 196 instead of the desired compound 195. 

The way to the 15-hydroxyderivatives was opened by N-alkylation of 225 with l-bromo-2-heptanone in ethanol to 229a in good yield. The reaction product 229a (free base m.p. 131 °C/hydrochloride m.p. 77 °C) was then used for the preparation of the 15-methyl-15-hydroxy and the 15-hydroxyderivatives. 

The dibromide derivatives of alkenyl esters spontaneously cleave in the cold to form a-bromo ketones and acyl halides. In this manner, 1-bromo-2-hexanone (67%) and l-bromo-2-heptanone (80%) are prepared. 

Ring contraction of appropriately substituted 1,6-di- or tetrahalocycloheptatrienes or -cyclo-heptanones provides access to the bicyclo[4.1.0]heptene system. Thus l-bromo-6-chlorocyclo-hepta-l,3,5-triene reacted with butyllithium directly to alford benzocyclopropene (la) in 50% yield, presumably via a norcaradiene intermediate. The 2-methyl derivative lb was... 

More recently, the Hager group (Theiler et al., 1978), has reported the partial purification of a bromoperoxidase enzyme from the red alga Bonnemaisonia hamifera. An in vitro bromination assay utilizing 3-keto-octanoic acid (57) as a substrate yielded, among other products, l-bromo-2-heptanone (58), which is known as a natural component of B. hamifera. In... 

Fischer indole synthesis to cyclohexanone-2-troponylhydrazone and dehydrogenation of the product to indolo[2,3-h]tropone the 8- and 10-isopropyl-, and 7-bromo-analogues, were also prepared. Treatment of the 2-troponylhydrazones of cyclo-heptanone and JV-benzylpiperidinone with acid gave analogous products. Tndolo[2,3-h]tropone was converted into benzo[h]-l-aza-azulene. ... 

---