Lee-Ruff E, Wells D
Department of Chemistry, York University, Toronto, Ontario, Canada.
Nucleosides Nucleotides Nucleic Acids. 2008 May;27(5):484-94. doi: 10.1080/15257770802088886.
The synthesis of a series of bicyclic nucleosides using photolytic ring-expansion of cyclobutanones is reported. The cyclobutanone precursors were prepared by [2+2] cycloaddition of a series of cyclic alkenes with chlorinated ketenes, derived from dichloro- and trichloroacetyl chloride. The synthesis of the nucleosides was achieved through photolysis of cyclobutanone precursors with 6-chloropurine by UV irradiation. The generality of this method was investigated and the absolute stereochemistry was assigned by NMR spectroscopy. The photoproducts demonstrated a marked preference for the 2'-exo conformation.
报道了通过环丁酮的光解扩环反应合成一系列双环核苷。环丁酮前体是通过一系列环状烯烃与由二氯乙酰氯和三氯乙酰氯衍生的氯化烯酮进行[2+2]环加成反应制备的。核苷的合成是通过用紫外线照射使环丁酮前体与6-氯嘌呤进行光解反应来实现的。研究了该方法的通用性，并通过核磁共振光谱确定了绝对立体化学。光产物显示出对2'-外式构象有明显的偏好。
