STEREOSELECTIVE ADDITION OF BENZONITRILE OXIDE AND N-BENZYL-C-PHENYLNITRONE TO (5RS,6SR)-5,6-DIHYDRO-6-ETHYL-5-METHYLPYRAN-2(2H)-ONE - CRYSTAL-STRUCTURE OF (1RS,4RS,5RS,6RS,9SR)-8-BENZYL-1,5-DIMETHYL-4-ETHYL-9-PHENYL-3,7-DIOXA-8-AZABICYCLO [4.3.0]NONAN-2-ONE
STEREOSELECTIVE ADDITION OF BENZONITRILE OXIDE AND N-BENZYL-C-PHENYLNITRONE TO (5RS,6SR)-5,6-DIHYDRO-6-ETHYL-5-METHYLPYRAN-2(2H)-ONE - CRYSTAL-STRUCTURE OF (1RS,4RS,5RS,6RS,9SR)-8-BENZYL-1,5-DIMETHYL-4-ETHYL-9-PHENYL-3,7-DIOXA-8-AZABICYCLO [4.3.0]NONAN-2-ONE
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DOI：
10.1039/p19850002763
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发表时间：
1985-12-01
期刊：
影响因子：
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通讯作者：
WILLIAMS, DJ
中科院分区：
文献类型：
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作者：
FRAY, MJ;THOMAS, EJ;WILLIAMS, DJ
氧化苯甲腈和N-苄基-C-苯基硝酮与(5R,6SR)-6-乙基-5,6-二氢-5-甲基-2H-吡喃-2-酮(4)的加成反应与烯丙基甲基取代基立体选择性地发生顺式反应。使用二异丙基氨基锂和碘甲烷对硝酮加合物 (7) 和 (8) 进行甲基化，涉及 C-1 构型的保留，尽管在后一种情况下发生少量开环和闭环，得到甲基化异恶唑烷 (11) 作为次要产物。 (1RS,4RS,5RS,6RS,9SR)-8-苄基-4-乙基-1,5-二甲基-9-苯基-3,7-二氧杂-8-氮杂双环[4.3.0]壬南-2-酮(10)的结构通过X射线结构测定确认。
Addition of benzonitrile oxide and N-benzyl-C-phenylnitrone to (5R,6SR)-6-ethyl-5,6-dihydro-5-methyl-2H-pyran-2-one (4) took place stereoselectively syn to the allylic methyl substituent. Methylation of the nitrone adducts (7) and (8) using lithium di-isopropylamide and methyl iodide involved retention of configuration at C-1 although a small amount of ring-opening and closing occurred in the latter case to give the methylated isozazolidine (11) as a minor product. The structure of (1RS,4RS,5RS, 6RS,9SR)-8-benzyl-4-ethyl-1,5-dimethyl-9-phenyl-3,7-dioxa-8-azabicyclo[4.3.0]nonan-2-one (10) was confirmed by an X-ray structure determination.