for the following products
5'-O-(4,4-Dimethoxytrityl)-2'-o-[(tert-butyl)dimethylsilyl]-n-isobutyrylguanosine-3'-(2-cyanoethyl-N,N-diisopropyl)phosphoramidite | 5'-O-Dmt-2'-tbdms-rg(N-ibu)-3'-cedpa | Ibu-G-CE-Phosphoramidite and 5'-O-DMT-2'-O-tert-Butyldimethylsilyl-N2-isobutyrylguanosine 3'-CE phosphoramidite
