1 -O-trityl

Bowden and Thomas report that the effect of methyl groups on the conductivity of trityl chloride in sulfur dioxide is in the order p>o>m> none.1 1 The trityl chloride-stannic chloride complex and a whole series of trityl bromides are strong electrolytes in sulfur dioxide.160-152 Benzhydryl chloride, ra-chlorobenzhydryl chloride, and -dimethylbenzhydryl chloride do not conduct in sulfur dioxide. Earlier reports to the contrary may have been due to the use of impure compounds.162 Dimesitylmethyl chloride has also been reported to conduct in sulfur dioxide.163... 

Ohrui and Fox128 reported that treatment of 2,3-O-isopropylidene-5-O-trityl-jS-D-ribofuranosyl chloride (171) with diethyl sodiomalonate in 1,2-dimethoxyethane gave an anomeric mixture of C-glycosyl compounds (172) which, when allowed to equilibrate in ethanol containing sodium ethoxide, gave the )3 anomer (173) as the preponderant product. Similar observations were made with the C-... 

The 1,2-O-cyanoethylidene method also became the basis for a polycondensation reaction, which allowed the synthesis of many polysaccharides [37]. When both the O-trityl and cyanoethylidene groups are present in the same molecule as in 31, polycondensation takes place under glycosidation conditions giving a polysaccharide chain, for example 32 (Scheme 5.11). 

In the second procedure13 (see Scheme 3), D-glucitol (10) was converted into 5-O-benzoyl-1,3 2,4-di-O-ethyl idene-6-O-trityl-D-glucitol (17) by successive treatment with acetaldehyde to produce 15, with chlorotriphenylmethane to provide 16, and with benzoyl chloride to afford 17. Selective removal of the trityl protecting group from 17, to give 18, followed by oxidation of 18, provided 19 which, on hydrolysis, afforded L-gulose (9). 

O-trityl-D-gaIactono-1,4-lactone (30c). Detritylation of 30c with F3B OEt2 caused 0-5 —> 0-6 acetyl migration, affording 30b, which was used for the preparation of 5-O-methyl-D-galactofuranose (39). 

Making use of a O-trityl-hydroxylamine linker, Meloni and Taddei reported the first example of Miller hydroxamate on solid phase (161, Scheme 73). /1-Lactams 162 and 163 were prepared on solid support starting from serine, threonine or other / -hydroxyacids derived from naturally occurring amino acids and a resin bonnd hydroxylamine 159. The ring closure of 160 was carried out under Mitsunobu conditions. 

The sulfoxide that has been studied was obtained by the oxidation of a sulfide, namely, (2S,6K)-6-(hydroxymethyl)-2-methoxy-1,4-oxathiane,47 synthesized from methyl 6-O-trityl-a-D-glucopyrano-... 

Selective tritylation of methyl oc-L-rhamnopyranoside yielded 57% of the 3-0-trityl derivative, together with 1 % of the 2-0- and 3 % of 4-0-trityl isomers. For methyl P-L-rhamnopyranoside, 34% of the 3-trityl and 17% of the 4-trityl ether were obtained [315]. Similarly, the 3,6-ditrityl ether is the major product of ditrityl-ation of methyl and benzyl a-D-mannopyranosides [316]. The corresponding a-D-glucopyranosides yielded the 2,6-di-O-trityl derivative, whereas both the 2,6- and 3,6-ditrityl ethers were isolated in the case of [Pg.237]

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