T-BuOK

Quininone (2). Potassium melal (10 g, 0 2S at g) was dissolved In t-BuOH (200 mL). The excess o< t-BuOH was removed in vacuum until a dry mobile powder was obtained. A suspension oi t-BuOK and qumlne 1 (32.4 g, O.t mol), benzophenone (91.0 g, 0 5 moQ in PhH (500 mL) was refluxed for 15-18 h under Ng The cooled mixture was poured into ice and extracted with 10% HCI until the HCI was coiortess. The aad extract was washed with EIzO and dripped with stirring into NH4OH and ice Extraction with EI2O, washing of the extract with brme and evaporation of the extract afforded a total of 30-32 g of 2 (95-98%), mp 106-108 C. 

Allylamines have been used as nitrogen protective groups. They can be removed by isomerization to the enamine (t-BuOK, DMSO) or by rhodium-catalyzed isomerization. ... 

Because of the increased acidity and reduced steric requirement of the carbohydrate hydroxyl, t-BuOK can be used as a base to achieve ether formation. 

Allyl ethers are isomerized by (Ph3P)3RhCl, and t-BuOK/DMSO in the following order " ... 

CH2=C=0, t-BuOK, THF. The 17a-hydroxy group of a steroid was acetylated by this method. 

R = OMe, AICI3, PhNMe2, CH2CI2, rt then t-BuOK or t-BuMgCl, 88-91% yield. 

Most applications of this derivative have been for the preparation and modification of amino acids, although some applications in the area of carbohydrates have been reported. The derivative is stable to -butyllithium, lithium diiso-propylamide, and t-BuOK. ... 

The modification of the Madelung indole synthesis achieved by introduction of an electron withdrawing group (EWG) at the benzylic carbon atom of the N-acylated-o-alkylanilines has been quite successful. Orlemans et al. reported that indoles were isolated in decent yields when the amides were treated with t-BuOK in THF for a period of 10 minutes at room temperature. ... 

The Madelung indole synthesis has been employed in the preparation of some complex indole systems. Uhle et al. reported the conversion of N-formyl-5,6,7,8-tetrahydronaphthylamine 28 into 1,3,4,5-tetrahydrobenz[c,ti]indole 29 with t-BuOK in 11% yield in regard to synthesis of ergot alkaloids. ... 

Carbanions of substituted diacetylenes 68 generated under the action of complex superbase -BuLi/t-BuOK/THF/hexane add to carbon disulfide to afford the intermediates 69 which further transform to thieno[2,3-i]thiophenes (70) (90DIS 91SC145). 

A five-step synthesis of ethyl ester of eyelie hydrazonie aeid 314 used in the synthesis of natural produets has been deseribed [94JCA(CC)1867]. The eonden-sation of methoxybutenone with EtCOaCN (t-BuOK, THF, —78°C) is eompleted with the formation of ketoester 310 in 72% yield. The addition of methanol to the latter (Triton B, MeOH, room temperature, 88%) and the reduetion with NaBH4 (EtOH, —78°C) leads to the aleohol 312, yield 90%. The dianion of 312 (EDA, THE, -78°C) reaets with t-butylazodiearboxylate (t-BuOaC—N=N—COaBu-t) to form adduet 313, the treatment of whieh with trifluoroaeetie aeid affords the ester 314 in 55% yield [94JCA(CC)1867]. 

Hydroxy group of rru -7,9u-H-7-(prepared from 7-formyl-2-(2-pyrimidyl)perhydropyrido[l,2-u]pyrazine by the treatment with MeOCH2P(Ph)3Cl in the presence of -Pr2NH in THF at 0°C, than with BuLi at room temperature (99MIP6). 

A mixture of 6-mesyl-6,7-dihydro-5/f-dibenz[ ,c]azepine (29, R = Ms 13.67 g, 50 mmol) in anhyd DMSO (160 mL) and t-BuOK (18.7 g, 165 mmol) was stirred for 45 min at 20 C under N2. Another portion of /-BuOK (2.65 g, 25 mmol) was added and stirring was continued for a further 45 min. The mixture was transferred to a separating funnel with ice-cold H20 (1.1 L) and extracted with Et20 (700 mL). The aqueous phase was extracted again with Et,0 (200 mL) and the combined ethereal extracts were then dried for 2 h (CaCl2) and evaporated to give the crude product as a pale-yellow oil (9.61 g, 99 %). which was purified bv distillation (bp 125 126/0.01 Torr) to give the product as colorless crystals yield 8.25 g (85 %) mp 84-85 C. 

To the crude product 2 (1.1 g, 3.8 mmol) was added excess t-BuOK in t-BuOH (150mL). The mixture was warmed on a steam bath for 15 min, poured into H20 (300 mL), then extracted with Et20. The Et20 extract was washed with H20, dried (K2C03), and evaporated to dryness. Recrystallization of the residue from EtOH (20 mL) afforded 3 as yellow crystals yield 313 mg (39%) mp 135-138 C. 

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