SYNTHESIS AND NMR-SPECTRA OF 2,3-DIHYDRO-1,3-METHANOINDENE DERIVATIVES AND 1,2,3,5-TETRAHYDRO-1,3-METHANOPENTALENE

2‐Lithiobicyclo[2.1.1]hexene, prepared from bicyclo[2.1.1]hexan‐2‐one, is the key intermediate in an efficient synthesis of interesting bicyclo[2.1.1]hexane derivative such as 1–3. Noteworthy is the reactivity of 3, which acts more as a 2π‐electron than as a 4π‐electron system toward olefins such as tetracyanoethylene. Furthermore, the new compounds have unusual 13C NMR spectra. (Figure Presented.) Copyright © 1990 by VCH Verlagsgesellschaft mbH, Germany