1-ethoxyethyl

Ethoxyethyl, 59 1-(2-Chloroethoxy)ethyl, 60 1 -[2-(Trimethylsilyl)ethoxy]ethyl, 61 1-Methyl-1-methoxyethyl, 61 1-Methyl-1-benzyloxyethyl, 62 1 -Methyl-1 -benzyloxy-2-fluoroethyl, 62... 

Methoxymethyl. 257 Benzyloxymethyl, 258 Methoxyethoxymethyl, 258 2-(Trimethylsilyl)ethoxymethyl, 259 Methylthiomethyl, 259 Phenylthiomethyl, 259 Azidomethyl, 260 Cyanomethyl, 260 2,2-Dichloro-1,1-difluoroethyl, 260 2-Chloroethyl, 261 2-Bromoethyl, 261 Tetrahydropyranyl, 261 1-Ethoxyethyl, 261 Phenacyl, 262... 

Similarly, the cross-coupling of N-protected 4-ethynylpyrazole with 1-(1-ethoxyethyl)-4-iodo- l//-pyrazole leads only to disubstituted butadiyne (2001 UP 1) (Scheme 50). 

In a reaction sequence202 protected a-hydroxy sulphones were alkylated, after which acid hydrolysis followed by mild basic hydrolysis gave ketones. The protecting group used was the 1-ethoxyethyl ether, and overall yields for the sequence were generally modest (equation 89). 

R,3S)-N-debenzoyl-N-tert-butoxycarbonyl-10-deacetyl-2-(1 -ethoxyethyl)-7,10-bis-(triethylsilyl)taxol (XXIII)... 

Ethyl vinyl ether is also useful for hydroxy group protection. The resulting derivative (1-ethoxyethyl ether) is abbreviated as the EE group.156 As with the THP group, the EE group introduces an additional stereogenic center. 

As an alternative to protection as ethers, alcohols can also be protected as acetals, the most common being tetrahydropyranyl ethers (THP-OR) and 1-ethoxyethyl ethers (EE-OR) (Table 7.7). Support-bound secondary aliphatic alcohols have been... 

The transfer of a carbamate moiety to olefins has been documented only in very few cases, using activated unsaturated substrates. For example, Yoshida and Inoue reported the selective (100%) formation of 1-ethoxyethyl N,N-dialkylcarbamate esters by the reaction of C02 (5 MPa) with ethyl vinyl ether and secondary amines R2NH (R = Me, Et) in the absence of any catalyst (Equation 6.11) [85]. 

In this reaction, carbamate esters were obtained after long reaction times (70 h), in 0.06-11% yield, depending on the olefin/amine molar ratio (l-10mol/mol) and temperature (308-353 K). Since 1-ethoxyethyl carbamate was formed as the sole regio-isomer product, but there was no formation of the 2-ethoxyethyl ester, the reaction was believed to proceed by an electrophilic addition to the vinyl ether of carbamic acid, formed by reversible reaction of C02 with amine (see Equation 6.1). 

Trifluoromethyl-P-lactam 63 was prepared in racemic form via a ketene-imine [2 + 2] cycloaddition, following previously published methods81 with modifications.46 The subsequent oxidative cleavage of PMP, acylation of NH with (f-Boc)20, hydrogenolysis over Pd/C, and protection as 1-ethoxyethyl ether gave N-f-Boc-P-lactam 63 in good overall yield (Scheme 13). 

A process according to claim 1, in which /<2 is chosen from methoxymethyl, 1-ethoxyethyl, benzyloxymethyl, (P-trimethylsilylethoxy)methyl, tetrahydropyranyl and 2,2,2-trichloroelhoxycarbonyl, and R% is chosen from trialkylsilyl groups in which each alkyl portion contains from one to three carbon atoms. 

---