Reaction of difluorocarbene with small bicyclic molecules

✍ Scribed by James E. Jackson; Ulf Misslitz; Maitland Jones Jr.; A. de Meijere

• Publisher: Elsevier Science
• Year: 1987
• Tongue: French
• Weight: 930 KB
• Volume: 43
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(01)89999-3

✦ Synopsis

Difluomoarbene reaote with 1.2.2-trimethylbioyaloU.l.Dlbutane to give the product of two bond aleavage. 1.1~difhmro-3,3,4-trimethyl-1, I-pentadiene in 3% yidli. Bicyclo[2.l.Olpentane ia even leee reeative. yielding l,l-difluorohexa-1,5diene in 08. 0.5% yield. Bioyolo[3.l.Olhexane does not reaot with difluorocarbene. Theoretical deecriptions of these reaotions are discussed. Introduotion Over the last several years we have oommuniaated a number of papers on the reactions M carbenee with carbon-carbon aingle bonds contained in highly strained ringr. 2.3 Wtth one exmp-lionSO expe&ental detafla have Been laoking and a variety of tines reacting with the vxrtous hydrocarbons hax been deearibeQ. Here we deport the details of Iha reaction of' a eingle carbene, difltirocarbene. with a epeotrum of compound6 containing small rings. Little previous work has been msported on the reaction of carbenee with carbon-c&bon single bonds and for good reason: the rea&n almoet doeanY occur! nNormaln C-C bonde dd'not reactsCg4 and for the reaction to ocour at all activation must be preeent. Thue mol&ulee contairiing exotic kinds of bonding are required and even in euoh ceeea yields are low. We -aBrB operating at the limit6 of reactivity even for such voracioue eleatrophilee ae oarbenea. Reaction of Difluorouarbene with Bicyalobutane Like methylene and dloarbomethorgcarben,&*= dMuolaarbensreacte*hbiuydObutaneeby two bond deavage. Thue CF2 &ebinae with 1.2;2-trknethylbicy&[l.l.Olbutane (1) to give l.l-di-fluolrr3.3,4-trkwthyl-1.4-pentadiene (2) in 3% yield. DEloo~waeg@xwlatedbythemethod of Burton, 5 under which conditions 1 waa apparently converted to vinylaycloproparies 5 and 4 ae eubstantial amounta of 5 and 6 were ieolated along tiih 2? Diene 2 wae independently aynthe!efsed