Premium
Thermochrome Furofurane, II. Synthese und Thermolyseverhalten substituierter Spirochinolether der Naphthalinreihe
Author(s) -
Laatsch Hartmut,
Ernst Bernd Peter
Publication year - 1992
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.1992199201207
Subject(s) - chemistry
Thermochromic Furofuranes, II. — Synthesis and Thermolytic Behavior of Spiroquinole Ethers with Naphthalene Nucleus To obtain further insight into the new photochromic system 2/3 , various 3,4‐disubstituted spiroquinole ethers 7 have been synthesized by oxidation of 2‐alkyl‐4‐methoxy‐1‐naphtholes 5 via the corresponding quinone methides 6 . Unlike 7a , the ethers 7b – d did not yield dimeric quinone methides or furofuranes (type 2/3 ) on heating, but decomposed by retro‐diene reaction yielding monomeric methides 6 . The sterically hindered methides 6e, 6f are stable yellow compounds; 6c rearranged forming 12 which led to the naphthopyranes 11a/11b on further reaction with 6c .