tall oil 2-[(tetrahydro-2H-pyran-2-yl) thio]ethyl esters

A photochromic compound is provided, which may be a pyran, an oxazine, or a fulgide.

A synthetic method of 2-methyl-6-tert-butyl-4-dicyanomethylene-4H-pyran is disclosed.

The compounds also have substituents at the 3 position of the pyran ring.

The haloenol lactone, E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyrane-2-one, is most preferred.

Described herein are compounds generally comprising an indeno[2',3':3,4]naptho[1,2-b] pyran structure.

Described herein are compounds generally comprising an indeno[2',3':3,4]naptho[1,2-b] pyran structure.

Described herein are compounds (III) comprising an indeno[2',3', 3, 4] naptho [1,2-b] pyran structure.

A synthetic method of 2-methyl-6-tert-butyl-4-dicyanomethylene-4H-pyran is disclosed.

Optional substituents can be present at the other positions of the indeno [2',3':3,4]naphtho [1,2-b]pyran structure.

Alternative embodiments include various substituents at other positions of the indeno[2',3':3,4]naphtho[1,2-b]pyran.

Group A consisting of benzene, cyclopentadiene, cycloheptatriene, furane, pyrane, cyclopentene, cyclopentane, cyclohexane, cyclohexene, cyclohexadiene, cycloheptane, cycloheptene, and cycloheptadiene.

The invention relates to pyran/dioxan derivatives and use thereof as components in liquid crystal media.

The invention relates to specific photochromic pyran derivatives and the use thereof in all forms of plastic, especially for ophthalmic purposes.

The invention relates to chiral 3,4-dihydro-2H-pyran compounds, to diastereomers thereof, and to the use of these compounds as chiral dopants for liquid crystal systems.