Alcohols, acetylation trityl ethers

Protection and deprotection oj 0-acetylation of alcohols and accu Trityl ethers are cleaved by ITV not affected. Discrimination of ary l (alkyl TBS ethers are selectively hy such amides by brief treatment witf Thioacetals are converted to car lodinations. In the preparat added. lodination of aromatic 1 -(tosyloxy)-1,2-benziodoxol-3( 1H iodination of 3,4-bis(trimethylsilyl i a combination of iodine and sih unsymmetrical 3,4-diarylthiophene a-Methoxy-a,P-unsaturated et (1 -methoxyalkylidene)-mngsten(O) the unsaturated esters. When iodim low. 

The Koenigs-Knorr101102 Reactions" of 3,4,6-Tri-0-acetyl-2-0-benzyl-a- (50a) and -/3-D-Glucopyranosyl Chlorides (50b) and the Perchlorate (50c) with Isopropyl Alcohol and Methyl Trityl Ether at 0°... 

Reactions were performed with 1 molar equivalent of isopropyl alcohol or methyl trityl ether. 6 Analyzed by gas chromatography (g.l.c.). c Analyzed by g.l.c. after acetylation. d Reactions were conducted in the presence of Drierite. Methyl trityl ether was used. 

The aziridine 12i has been derived from the trans amino alcohol 12h by the two-step, one-pot process i) selective protection of the amino functionality with trityl chloride and ii) mesylation of the hydroxyl in the presence of triethylamine. Under these conditions, the mesylate intermediate has been converted to aziridine 12i. Treatment of 12i with /-pentyl alcohol in the presence of 1.5 equiv of BF3-Et20 followed by acetylation of the crude product provides the ether 121. Finally, reduction of the azide functionality and saponification of the ester group in 121 give GS4071,12. 

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