Isopropoxy

The reaction of 1-isopropoxy-l-trimethylsiloxycyclopropane (1, R = i-Pr) with TiCl yields the titanium homoenolate of isopropyl propionate 2 (R = i-Pr) and Me3SiCl (Eq. see 9). That of 23, in contrast, yields a considerable fraction of the homoenolate of silyl propionate as well, Eq. (66) [19]. Apparently, the loss of an isopropyl group from an oxygen-stabilized cationic intermediate competes with that of the silyl group with bulky substituents. 

In the third series, 1-methoxy-, 1-ethoxy-, 1-isopropoxy-, 1-tertbutoxy- and l-(chloromethyl)silatranes were examined in comparison with well-known preparations widely used in therapy such as Vishnevsky ointment, synthomicyn emulsion, and cygerol (Table 14),... 

All the data obtained have shown that some silatranes, especially 1-ethoxy-, 1-isopropoxy- and 1 (chloromethyl)silatrane effectively intensify the hair growth in animals without producing any side effects (Fig. 13). This suggested that they should be tried as possible medicinal preparations in treatment of premature hair loss (alopecia). 

Irradiation (A, > 280 nm) of a hexane/isopropyl alcohol solution of the disilene precursor ( )-14 (Scheme 8) in a quartz tube at room temperature produced threo-1-isopropoxy-1,2-dimethyl-1,2-diphenyldisilane 37a, which is the product of syn addition of isopropyl alcohol to ( )-16 together with a small amount of the erythro-isomer 38a (37a/38a => 99/1, 62% yield). High syw-addition diastereoselectivity was also found... 

Tellurium tetrachloride and 1-isopropoxy-l-trimethylsiloxycydopropane, an acetal of cyclopropanone, reacted in dichloromethane solution at 20° to give bis[2-isopropoxy-curboriylethyH tellurium dichloride2. 

As an example, a reaction of benzylmagnesium chloride with 1-(1-isopropoxybenzyl)benzotriazole gave 1 -isopropoxy-1,2-diphenylethane, b.p. 70°/0.04 mmHg (85%). 

To a suspension of bismuth chloride (276 mg, 0.874 mmol), dried at ca. 300°C for 10 min, in chloroform (1 ml) was added 1-isopropoxy-l-trimethylsiloxycyclopropane (0.180 ml, 1.874 mmol) at —60°C with stirring. The mixture was agitated under ultrasonic irradiation for 1.5 h at room temperature. The solvent was removed, and the residual white solid was recrystallized from benzene to give the expected alkyldichlorobismuthine (89%), m.p. 144—145°C (decomp.) [850M641]. 

To a stirred solution of 3,3 ,4,4 -tetra-n-pentyloxybiphenyl (383, 3.32 g, 6 mmol) and 1-isopropoxy-2-methoxybenzene (382, 1.66 g, 10 mmol, 1.67 eq.) in dichloromethane (50 ml), anhydrous iron(III) chloride (5.00 g, 30 mmol) was added slowly and the reaction mixture was stirred at room temperature overnight. Then, the mixture was poured into methanol (200 ml), and cooled to 0 °C. The solid was filtered off, washed with cold methanol, purified by column chromatography over silica gel using dichloromethane / petroleum ether (3 1), to give 2.67 g (72%) of pure 384 as a white solid, m.p. 118.5-119.5 °C. 

Isopropoxy-l-methylethoxy l-(p-toluene-sulfonyl)propyl nitroxide CH,... 

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