Purines. XVII. Kinetic studies of the base-catalyzed conversion of 1-alkyladenosines into N-aklyladenosines: Effect of substituents on the rearrangement rate.

• 藤井 澄三

• 板谷 泰助

• 斎藤 徹

抄録

The rates of the Dimroth rearrangements of 1-alkyladenosines (Ie, f) and 1-alkyl-9-methyladenines (Ia-d) at various pH's and ionic strength 1.0 at 40° have been measured. It has been shown that all reactions obey good pseudo-first-order kinetics and follow the rate law given by k⁽⁰⁾_obsd=k⁽⁰⁾_ionic [I·H⁺] [OH^-]+k⁽⁰⁾_neut [I] [OH^-] where k⁽⁰⁾_obsd is the observed limiting specific rate for zero buffer concentration ; [I·H⁺] is the fraction of the base protonated at each pH ; [I], the fraction present as free base. Comparison between the individual second-order rate constants thus obtained (Table III) has revealed that attack of hydroxide ion on the protonated species is faster than on the neutral species by a factor of 90-1100 and that the former is affected by the electronic property of a substituent at the 1-position, whereas the latter is influenced by a steric factor. The rate of the rearrangement is enhanced by the benzyl group at the 1-position at near neutrality and by the β-D-ribofuranosyl group at the 9-position at all pH's examined.

収録刊行物

• ＣＨＥＭＩＣＡＬ　＆　ＰＨＡＲＭＡＣＥＵＴＩＣＡＬ　ＢＵＬＬＥＴＩＮ

  ＣＨＥＭＩＣＡＬ　＆　ＰＨＡＲＭＡＣＥＵＴＩＣＡＬ　ＢＵＬＬＥＴＩＮ 23 (1), 54-61, 1975

  公益社団法人 日本薬学会

キーワード

• Drug Discovery
• General Chemistry
• General Medicine

詳細情報

• CRID: 1390001204170284800
• NII論文ID: 110003621644
• NII書誌ID: AA00602100
• DOI: 10.1248/cpb.23.54
• COI: 1:CAS:528:DyaE2MXhsFCqsLo%3D
• ISSN: 13475223
• ISSN: 00092363
• Web Site: http://www.jstage.jst.go.jp/article/cpb1958/23/1/23_1_54/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/1975085018
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可