Cleavage of tert-butyldimethylsilyl ethers by tetrafluoroborate salts

Primary and secondary alcohols can be regenerated from their corresponding $\text{tert}$-butyl silyl ethers by treatment with tetrafluoroborate salts.     

The tert-butylation of nicotine: novel reaction pathways and racemization studies

The reaction of nicotine with $\text{tert}$-butyllithium gives 6-$\text{tert}$-butylnicotine ($\text{2}$) and two novel pyrrolidine ring cleaved products, $\text{3}$ and $\text{4}$; mechanisms for the racemization of $\text{1}$, $\text{2}$, and $\text{4}$ were elucidated by reacting $\text{tert}$-butyllithium with nicotine-2′-d₁.     

Biomimetic entry to acyclic terpene synthesis a novel rearrangement of allyl ether catalyzed by organoaluminium reagents

The intramolecular prenyltransfer reaction is accomplished by the rearrangement of allyl ethers with (2,6-di-$\text{tert}$-butyl-4-methylphenoxy)methylaluminum trifluoromethanesulfonate. The present method provides a simple and highly efficient synthesis of lavandulol.     

Reversible nethide shifts in the 2-tert-butyl-2-adamantyl cation

Treatment of either 3-$\text{tert}$-butyl-2-adamantanol or 2-isopropenyl-2-methyladamantane with acid in the presence of a reducing agent (hydrogen iodide or tri-$\text{2}$-hexylsilane) yielded 2-$\text{tert}$-butyladamantane as the major or exclusive product. Both precursors gave the 2-$\text{tert}$- butyl-2-adamantyl cation at ?78°C in FSO₃H-SbF₅-SO₂ClF.     

Co2(CO)8 Catalyzed reaction of oxetanes with trialkylsilanes

Dicobalt octacarbonyl catalyzed silyl-hydroformylation of oxetanes can be controlled by the choice of trialkylsilane. Triethylsilane gives 1,4-$\text{bis}$-silyl ethers while $\text{t}$-butyl-dimethylsilane yields silyl enol ethers.     

The survival of tert-butyldimethylsilyl group of silyl enol ethers in the reaction with dimethyl(methylene)ammonium iodide. Regioselective synthesis of tert-butyldimethylsilyl enol ethers containing an amino group.

$\text{t}$-butyldimethylsilyl enol ethers containing an amino group were obtained in good yields (70–90%) by the reaction of $\text{t}$-butyldimethylsilyl enol ethers with dimethyl(methylene)ammonium iodide (the Eschenmoser salt).     

Synthesis of t-butyldimethylsilyl enol ethers from sterically hindered ketones

Ketones react rapidly with $\text{t}$-butyldimethylsilyl triflate and amine bases to form $\text{t}$-butyldimethylsilyl enol ethers in high yields.     

Sesquiterpenes from termite soldiers. Structure of amiteol,a new 5β, 7β, 10β-eudesmane from amitermesexcellens

The defense secretions of termite soldiers in the genera $\text{Amitermes}$, $\text{Noditermes}$, and $\text{Prorhinotermes}$ contain sesqueterpene hydrocarbons, alcohols and ethers. Three new eudesmanes possessing the hitherto unknown 5β, 7β, 10β configuration were identified from $\text{Amitermes}$$\text{excellens}$.     

Synthesis of β=iodo-t-butyl and methyl ethers from the reaction of alkenes with t-butyl and methyl hypoiodites

$\text{t}$-Butyl or methyl hypoiodite, generated from potassium t-butoxide or sodium methoxide and iodine monochloride, react with olefins via a bridged iodonium ion intermediate giving the $\text{trans}$-vicinal iodo -$\text{t}$-butyl or -methyl ethers.     

Action of tert-butyl azidoformate on the conjugate bases of 1,2,3,4-tetrahydro-9H-carbazole and other indole derivatives

tert-Butyl azidoformate ($\text{2}$) reacts with the conjugate bases of $\text{3a}$, $\text{7a}$, $\text{9}$ (R¹ = R² = CH₃), and $\text{9}$ (R¹ = CH₃, R² = H) to give products [$\text{4}$, $\text{8}$, $\text{12}$, and $\text{14}$, respectively] in addition to the expected N-(tert-butoxycarbonyl)indole derivatives.     

Selective reduction of the N-O bond in n-oxides and in nitrones by sodium hydrogen telluride

Sodium hydrogen telluride reduces $\text{tert}$.-amine $\text{N}$-oxides to the corresponding amines in very high yield, but does not reduce sulphoxides. This reagent also reduces nitrones to $\text{sec}$.-amines at pH6 and to imines at alkaline pH (10–11).     

Synthesis and characterization of 4-dimethylamino-N-triphenylmethylpyridinium chloride,a postulated intermediate in the tritylation of alcohols

4-Dimethylamino-$\text{N}$-triphenylmethylpyridinium chloride ($\text{1}$) reacts with primary but not secondary alcohols to produce trityl ethers in good yield; in addition, amines may be selectively $\text{N}$- tritylated witth $\text{1}$ in the presence of alcohols.     

Isolation and structures of trans-laurencenyne,a possible precursor of the C15 halogenated cyclic ethers,and trans-neolaurencenyne from laurencia okamurai

Isolation and structural elucidation of two new acetylenic polyenes, $\text{trans}$-laurencenyne $\text{1}$ and $\text{trans}$-neolaurencenyne $\text{2}$ from the marine red alga $\text{Laurencia okamurai}$ were carried out, the former compound $\text{1}$ very recently being proposed to be a biosynthetic precursor of the C₁₅ halogenated cyclic ethers, $\text{7}$ and $\text{8}$.     

New fluoride ion-catalyzed reaction of f-alkylacetylenes with silyl enol ethers. An efficient route to f-alkyl-substituted propargylic alcohols and α-hydroxy ketones

Treatment of $\text{F}$-alkylacetylenes, generated $\text{in}$$\text{situ}$ from 1$\text{H}$-$\text{F}$-1- alkenephosphonates, with silyl enol ethers in the presence of a catalytic amount of tetrabutylammonium fluoride gives good yields of $\text{F}$-alkyl-substituted propargyl alcohols or 4-(1$\text{H}$-$\text{F}$-alkylidene)-1,3-dioxolane derivatives, the latter being converted to tie corresponding α-hydroxy ketones.     

Highly crowded enolates from reaction of di-tert-butylketene with alkyllithium reagents

Di-$\text{tert}$-butylketene reacts with alkyllithiums to give enolate intermediates which can be captured by silylation or alkylation.     

Hindered amines. General synthesis of α-(tert-butylamino)-isobutyramides

α-($\text{tert}$-Butylamino)-isobutyramides ($\text{1}$) can be prepared from α-haloisobutyramides ($\text{2}$) and $\text{tert}$-butylamine with sodium hydroxide in Favorskii-like reactions.     

Studies in claisen rearrangement - novel thermal and mercuric trifluroacetate induced transformations of 2,4-di(N-aryl)amino-1,3,5-triazin-6yl-prop-2-y

The thermal rearrangement of 2,4-di(N-aryl)amino-1,3,5-triazin-6yl-prop-2-ynyl ethers $\text{1}$ yield a mixture of 6-methyleneimidazo(1,2-a)-1,3,5-triazine-4-one $\text{6}$ and 6-methylimidazo(1,2-a)-1,3,5-triazine-4-one $\text{7}$, whereas under the influence of mercuric trifluroacetate the ethers $\text{1}$ yield only $\text{6}$, at room temperature. Mechanisms invoking [3,3] sigmatropic rearrangement of ethers $\text{1}$ were proposed to account for the product formation.     

The asymmetric epoxidation of tert-butyl substituted allylic alcohols

The response of the asymmetric epoxidation reaction to steric bulk in the substrate is tested by use of allylic alcohols with $\text{tert}$-butyl groups at each one of four possible positions.     

Isolation of a crystalline thiete and its ‘open’ isomer; Photoproducts of xanthenethione and bis(tert-butylthio)ethyne

Irradiation of xanthenethione $\text{1}$ with bis(tert-butylthio)ethyne $\text{2}$ yielded both the expected α,β-unsaturated dithioester $\text{4b}$ and surprisingly its proposed intermediate thiete $\text{3b}$ as crystalline compounds. In solution an equilibrium between both compounds has been observed.     

Photocycloaddition reactions of the first stable thioaldehyde: 2,4,6-tri(tert-butyl)thiobenzaldehyde with substituted allenes

Irradiation of 2,4,6-tri-(tert,-butyl)thiobenzaldehyde $\text{1}$ with some alkoxy-, alkylthio-, and phenyl-allenes $\text{2}$$\text{a}$-$\text{i}$ gave one stereoisomer of a (2+2)-cycloadduct, viz. thietane $\text{3}$ in high yields (75–95%). Ringclosure is in agreement with MNDO-calculations.