Thermochromic Furofurans. IV. Approach to the synthesis of bridgehead substituted furo[3,2-b]furans and side products of McMurry reactions
作者:Hartmut Laatsch、Antti Talvitie、Andreas Kral、Bernd-Peter Ernst、Mathias Noltemeyer
DOI:10.1002/prac.19963380127
日期:——
Substituted dihydroxystilbenes 2 are suitable starting materials for the synthesis of photochromic systems derived from 3/4. Attempts to couple the naphthones 8a-8e by the McMurry reaction with TiCl3/LiAlH4 yielded mainly reduction products such as 8f, g or 9. However, the furofuran 3b was isolated when using the zinc-copper couple for reduction. The helicene 11 was formed as an unexpected byproduct in the McMurry reaction of the pivaloylnaphthalene 8d.