Ring synthesis 2.3.4.5.7- pentamethyl

Lumazine, 1,3,6,7,8-pentamethyl-5,6,7,8-tetrahydro-rearrangement, 3, 308 Lumazine, 5,6,7,8-tetrahydro-autoxidation, 3, 308 oxidation, 3, 306 Lumazine, 1,3,6,7-tetramethyl-ring transformations, 3, 308 Lumazine, 1,3,5,6-tetramethyl-5,6,7,8-tetrahydro-synthesis, 3, 316 Lumazine, 2-thio-reactions, 3, 300 sulfurization, 3, 296 Lumazine, 4-thio-methylation, 3, 299 reactions, 3, 300 Lumazine, 1,3,7-trimethyl-acylation, 3, 290 Lumazine, 1,6,7-trimethyl-bromination, 3, 302 synthesis, 3, 295 Lumazine, 3,6,7-trimethyl-... 

In CHEC-II(1996), there are two reactions involving the synthesis of 2,3-dihydro-l//-l,3-diboroles by transformation of other rings <1996CHEC-II(3)767>. One of these reactions involves thermal ring contraction of 1,4,5,6-tetra-methyl-l,2,3,4-tetrahydro-l,4-diborinine 66 at 160°C to 4,5-diethyl-l,2,3-trimethyl-2,3-dihydro-l//-l,3-diborole 67. Uhm heated a solution of compound 66 in toluene in a pressure tube at the same temperature and obtained 1,2,3,4,5-pentamethyl-2,3-dihydro-l//-l,3-diborole 68 (Scheme 11) <2005JKC329>. 

Probably the first report on the use of a metaUocene in zeolite synthesis dates back more than ten years [124]. In the past few years, however, essentially two groups reported on the influence (i.e. structure directing properties) of cobalt metallocene compounds in the synthesis of zeolites and zeolite-like materials [e.g. 125-128]. In none of these studies had a new framework topology been synthesized. However, very recently Balkus and coworkers reported the synthesis of the first fourteen-membered ring zeolite, which they called UTD-1 (University of Texas at Dallas No. 1) [129-132]. UTD-1 was synthesized with a quite unusual template, viz. with bis(pentamethyl-cyclopentadienyl)cobalt(III) hydroxide [129-132]. Both the essentially pure-silica version and high-silica derivatives have been prepared. A typical synthesis of the all-silica version com-... 

Miscellaneous Nitrogen Ring Systems.—A synthesis of the bicyclic amidine 3,3,6,9,9-pentamethyl-2,10-diazabicyclo[4,4,0]dec-l-ene has been described/ This base, and the salts prepared from it, show solubility characteristics which make it a potentially useful reagent for salt formation of carboxylic acids. Various derivatives of the amidine were prepared, with the stable a-nitronyl nitrosium cation as possibly the most interesting, as its reactivity towards olefins and dienes resembles those of singlet oxygen (Scheme 76). 

---