THE ALLYLIC PROTECTION METHOD IN SOLID-PHASE OLIGONUCLEOTIDE SYNTHESIS - AN EFFICIENT PREPARATION OF SOLID-ANCHORED DNA OLIGOMERS

The first efficient synthesis of solid-anchored DNA oligomers has been realized; it relies on the use of allyl and (allyloxy)carbonyl groups as protectors of intemucleotide linkage and nucleoside bases, respectively, in conjunction with palladium chemistry. The preparation is performed via a phosphoramidite approach on controlled pore glass supports with a long-chain alkylamine spacer. The fully protected DNA is deblocked on the solid supports by removal of the allylic protecting groups by treatment with a mixture of the tris(dibenzylideneacetone)dipalladium(0)-chloroform complex, triphenylphosphine, butylamine, and formic acid at 50 °C for 0.5-1 h. Exposure of the solid-bound materials to concentrated ammonia at room temperature for 2 h affords free DNAs of excellent purity. The efficiency of this method has been demonstrated by the synthesis of d(5′CAAGTTGATGAACAATACTTCATACCTAAACT3′) (32mer), d(5′TATCGGACACGTAACCCTCCCATGTCGATGCAAATCTTTAACA3′) (43mer), and d(5′TATGGGCCTTTTGATAGGATGCTCACCGAGCAAAACCAAGAACAACCAGGAGATTTTATT3′) (60mer). © 1990, American Chemical Society. All rights reserved.