Preparation of perfluoroalkylated dithioketals and their synthetic utilities

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123

PREPARATION

OF PERFLUOROALKYLATED

DlTHIOKETALS

AND THEIR SYNTHETIC UTILITIES

I. H. Jeong, Y. K. hIin, Y. S. Kim and K. Y. Cho Korea Research Institute of Chemical Technology, P.O. Box 9, Daedeog-Danji, Daejeon, Korea 305406

The perfluoroalkylated of perfluoroalkylated

dithioketals

1 were prepared in moderate to good yields from the reaction

ketones with thiols (2 eq.) in the presence of AlCl, (1 eq.) at

-78°C followed by slowly warming to room temperature. of organolithium formation

reagents, such as alkyl, aryl, vinyl and acetylenic

of E and Z mixture of corre,ponding

sulfides 2 in good to excellent a-perfluoroalkylated

yields.

P-fluorinated

ketones 3 in moderate yields.

were treated with a variety of nucleophiles, were formed in good to excellent yields.

wR + PhSH

AlC1,/CH2C12

RF=F,CS R=CH,.

n-C,Hs.

-@I”

-78’C-Wr.t.

*

vinyl or

On the other hand, reaction of 1 with Raney

p,B -difluorinated

vinyl sulfides 4, which are possible intermediate

presented.

lithium, resulted in the

or P-perfluoroalkylated

Hydrolysis of 2 with cont. &SO4 provided a-fluorinated

nickel in reflux acetone afforded unexpected

RFC~C

Subsequent treatment of 1 with a variety

or B-fluoro-p -perfluoroalkylated

for the formation of 2. in good yields.

E and Z mixture of corresponding The scope and limitation

When 4

vinyl sulfides 5

of described reactions will be