title: Synthesis of 2'-O-methoxyethylguanosine using a novel silicon-based protecting group.
abstract: A short and efficient synthesis of 2'-O-methoxyethylguanosine (8) is described. Central to this strategy is the development of a novel silicon-based protecting group (MDPSCl(2), 2) used to protect the 3',5'-hydroxyl groups of the ribose. Silylation of guanosine with 2 proceeded with excellent regioselectivity and in 79% yield. Alkylation of the 2'-hydroxyl group of 6 proceeded with methoxyethyl bromide and NaHMDS and afforded compound 7 in 85% yield, without any noticeable cleavage of the silyl protecting group and without the need to protect the guanine base moiety. Finally, deprotection of 7 was achieved using TBAF and produced 8 in 97% yield.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla 92093-0358, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Wen
authors.forename: Suetying
authors.initials: S
authors.lastname: Chow
authors.forename: Yogesh S
authors.initials: YS
authors.lastname: Sanghvi
authors.forename: Emmanuel A
authors.initials: EA
authors.lastname: Theodorakis
mesh_terms: D000478:Alkylation; D006151:Guanosine / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D012825:Silicon / Q000737:chemistry*
chemical_list: D006151:Guanosine; D012825:Silicon