Trimethyl-l-butanol

The asymmetric nickel-catalyzed hydroalumination of prochiral terminal alkenes using adducts of BujAl and chiral amines was reported in 1981 [74], Among the different amines investigated, (-)-N,N-dimethylmenthylamine (DMMA) gave the best enantioselectivities. For example, reaction of 2,3,3-trimethyl-l-butene (39) at room temperature with 0.33 equiv. of the DMMA/iBu3Al adduct in the presence of 0.6 mol% of Ni(mesal)2 gave, after oxidation of the intermediate organoaluminum compounds, 2,3,3-trimethyl-l-butanol 40 in 76% yield and 27% ee (Scheme 2-19). 

An important result is the hydroboration of 2,3,3-trimethyl-l-butene with catecholborane in the presence of [Rh(cod)Cl]2 2 Diop leading to 2,3-trimethyl-l-butanol with 69% ee112. Other asymmetric hydroborating agents do not show a comparable cnanlioseleclivity in reactions with simple 2-methyl-1-alkenes. 

Treatment of [l- C]2,3,3-trimethyl-2-butanol with different hydrochlorina-ting agents gave products in which the distribution of label showed the sym-... 

Uusi-Kyyny, P. Pokki, J.-P. Aittamaa, J. Liukkonen, S. Vapor-Uquid equilibrium for the binary systems of 2-methyl-2-propanol + 2,2,4-trimethyl-l-pentene at 333 and 348 K and 2-butanol + 2,2,4-trimethyl-l-pentene at 360 K J. Chem. Eng. Data 2001,46, 686-691... 

Heating 3,4-bis(phenylsulfonyl)furoxan with a solution of sodium butoxide in butanol followed by reduction with trimethyl phosphite gives furazan 281 (Scheme 183). Compound 281 was converted into dialkoxy derivative 282 with the lithium salt of ( )-l-azabicyclo[2.2.2]octan-3-ol in 33% overall yield (96W012711, 97EUP773021, 98JMC379). 

From 3,3-dimethyl-2-butanol, the major product of rearrangement is 2,3-dimethyl-1-butene. The distribution of the primary dehydration products is far from equilibrium. The maximum ratio of 2,3-dimethyl-1-butene to 2,3-dimethyl-2-butene obtained from 2,3-dimethyl-2-butanol is about 10. This is higher than that to be expected if a proton is removed from the l,l,2-trimethyl-2-propyl carbonium ion in a statistical manner. The maximum ratio of the two olefins obtained from 2,3-dimethyl-2-butanol is also about 10. Hence it can be argued that the high yield of 2,3-dimethyl-1-butene from 3,3-dimethyl-2-butanol does not necessarily rule out a classical carbonium ion mechanism. It is very unlikely, however, that the same intermediate is involved from both alcohols. If such were the case the product of dehydration of 2,3-dimethyl-2-butanol would contain appreciable amounts of 3,3-dimethyl-l-butene. 

In the following, some applications are summarized (Scheme 31). 1-trimethyl-siloxy-bicyclo[4.1.0]-heptane (218) gives after hydrolysis l-hydroxy-bicyclo[4.1.0]-heptane (25J)151, ls2> but further treatment with potassium t-butanolate/ether... 

Oxo-l,3,3-trimethyl-bicyclo[2.2.1]heptan (Fenchon) wird dagegen durch Kalium/HMPT/tert.-Butanol zu endo-2-Hydroxy-l,3,3-trimethyl-bicyclo[2.2.1]heptan (a-Fenchol) (87% d.Th.) reduziert2. 

Benzyl tiglate Benzyl valerate Bicycle [2.2.2]-5-octene-2-carboxylic acid, 1(or 4)-methyl-4(or 1)-(1-methylethyl) methyl ester Bicyclopentylone Bicyclopentylyl butenoate y-Bisabolene Bitter almond (Prunus amybdalus) extract L-Borneol L-Bornyl acetate Bornyl isovalerate Bromo-D-camphor B-Bromostyrene Buchu leaves oil Butanol, 2-methyl-4-(2,2,3-trimethyl-3-cyclopentenyl)- p-t-Butyl acetophenone... 

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