264
Y. Yokoyama
Chart 15.6 Absolute stereochemistry of the major and minor closed forms generated in HSA, their
properties and the chemical correlation pathways between the closed forms. Reproduced from Ref.
[29] with permission from the Royal Society of Chemistry
15.4 Short-Step Construction of Photochromic Hexatriene
Skeletons
In order to realize “integrated multi-responsive photochromic systems,” a strong
requirement is for the synthesis of photochromic molecules be easy. Here, we show
the results of our efforts to develop facile and simple ways for the synthesis of
the hexatriene skeleton which may exhibit either thermally irreversible or thermally
reversible photochromism depending on their electronic/steric nature.
15.4.1 One-Step Assembly of Arylbutadienes [32]
We have previously reported the synthesis of a thermally irreversible photochromic
arylbutadiene 10o [33]. It exhibited thermally irreversible photochromism, and
its absorption maximum wavelength was 445 nm in toluene. If the substituents
which may induce electronic perturbation to the π-conjugation system such as the
Y. Yokoyama
Chart 15.6 Absolute stereochemistry of the major and minor closed forms generated in HSA, their
properties and the chemical correlation pathways between the closed forms. Reproduced from Ref.
[29] with permission from the Royal Society of Chemistry
15.4 Short-Step Construction of Photochromic Hexatriene
Skeletons
In order to realize “integrated multi-responsive photochromic systems,” a strong
requirement is for the synthesis of photochromic molecules be easy. Here, we show
the results of our efforts to develop facile and simple ways for the synthesis of
the hexatriene skeleton which may exhibit either thermally irreversible or thermally
reversible photochromism depending on their electronic/steric nature.
15.4.1 One-Step Assembly of Arylbutadienes [32]
We have previously reported the synthesis of a thermally irreversible photochromic
arylbutadiene 10o [33]. It exhibited thermally irreversible photochromism, and
its absorption maximum wavelength was 445 nm in toluene. If the substituents
which may induce electronic perturbation to the π-conjugation system such as the