17 ペニシリン-α(R)-スルフォキシドの選択的合成 : ペニシリンからセファロチンへの変換
書誌事項
- タイトル別名
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- 17 SELECTIVE SYNTHESIS OF PENICILLIN α(R)-SULFOXIDES : CONVERSION OF PENICILLIN TO CEPHALOTHIN
説明
Selective synthesis of 2β-functionalizedmethyl penicillin α-sulfoxides 15, which could be important intermediates for conversion of penicillins to cephalosporins, was accomplished as follows. Oxidation of N-nitroso penicillins with m-chloroperbenzoic acid, followed by reductive removal of the nitroso group gave penicillin α-sulfoxides selectively. Thus, 16 was converted to 21 and 19 in the ratio of 5:1, while 23 and 25 were transformed exclusively to α-sulfoxides 24 and 27, in 66% and 50% (from 22) yield respectively. Conversion of 25 to 31 (and thus to cephalothin 2) was achieved via disulfide 29 in 43% yield (AgF) or via 29 and 30 in 20% yield. Similarly, 24 could be transformed to 33, but further conversion to 37 could not be achieved. When 24 was treated with AgClO_4 in dioxane, a ring-expanded product 35 was obtained. 35 has been known as a versatile precursor of cephalosporins. Reaction of 24 with P(OEt)_3 gave 39 in good yield, whose thiazoline ring could be opened and traped as Ag-salt 40 and both 39 and 40 were cyclized to 41. Ozonolysis of 39 gave enol 43 which was converted to 3-hydroxycephem 42.
収録刊行物
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- 天然有機化合物討論会講演要旨集
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天然有機化合物討論会講演要旨集 21 (0), 120-127, 1978
天然有機化合物討論会実行委員会
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詳細情報 詳細情報について
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- CRID
- 1390282681051365248
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- NII論文ID
- 110006677963
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- ISSN
- 24331856
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- 本文言語コード
- ja
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- データソース種別
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- JaLC
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可
