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Formation of Fluorinated 1‐Oxaspiro[2.5]octa‐4,7‐dienes from Polyfluorinated Cyclohexa‐2,5‐dienones with Diazomethane and Reactions with Aryl and2‐Chloroethyl Isocyanates
Author(s) -
Kovtonyuk Vladimir N.,
Kobrina Ljubov S.,
Kataeva, Olga M.,
Haufe Günter
Publication year - 2005
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200400559
Subject(s) - chemistry , diazomethane , substituent , aryl , medicinal chemistry , lithium (medication) , diastereomer , lithium diisopropylamide , organic chemistry , medicine , alkyl , endocrinology , ion , deprotonation
The reactions of four polyfluorinated cyclohexa‐2,5‐dienones 1a – 1d , additionally substituted with an electron withdrawing substituent at the 4‐position, with diazomethane give mixtures of two diastereomeric fluorinated 1‐oxaspiro[2.5]octa‐4,7‐dienes 2 and 3 . Compounds 2a / 3a and 2b / 3b react with aryl and 2‐chloroethyl isocyanates in the presence of lithium chloride or sodium pentafluorophenoxide to form fluorinated dihydro‐1,3‐benzoxazol‐2(3 H )‐ones 5a – 5c as the major products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)