Approach to the Synthesis of Bridgehead Substituted Furo[3,2-b]furans and Side Products of McMurry Reactions

Article abstract of DOI:10.1002/prac.19963380127

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 by-product in the McMurry reaction of the pivaloylnaphthalene 8d.