Acetaldehydes mercaptals

Mercaptals, CH2CH(SR)2, are formed in a like manner by the addition of mercaptans. The formation of acetals by noncatalytic vapor-phase reactions of acetaldehyde and various alcohols at 35°C has been reported (67). Butadiene [106-99-0] can be made by the reaction of acetaldehyde and ethyl alcohol at temperatures above 300°C over a tantala—siUca catalyst (68). Aldol and crotonaldehyde are beheved to be intermediates. Butyl acetate [123-86-4] has been prepared by the catalytic reaction of acetaldehyde with 1-butanol [71-36-3] at 300°C (69). 

Mepiquat chloride, 13 43t, 54-55 Mepiquat dichloride, 21 127 Mercaptals, production from acetaldehyde, 1105... 

Mercaptals and Mercaptols.—Ethylidene mercaptan is ordinarily obtained as the thio-ether by the action of ethyl mercaptan on acetaldehyde ... 

The cyclic mercaptal of acetaldehyde (2-methyl-l,3-dithiane) is oxidized by m-chloroperoXybenzoic acid or sodium periodate to a mixture of diastereomeric cis and monosulfoxides (equation 569) [323]. 

When acetals of aldehydes or ketones are heated with thiols in a bomb tube at 100-130° the OR groups are replaced by SR, this process having been used to provide acetaldehyde diethyl mercaptal (84% yield), acetone diethyl mercaptol (81%), and triethyl trithioorthoformate (87%).425... 

Treatment of acetals with thiols in excess produces an equilibrium mixture from which the corresponding dithioacetal may be obtained a favourable case from this point of view is the conversion of formamide acetals R2NCH(OMe)2 into corresponding mercaptals. Vinyl sulphides CH2=CHSR give acetaldehyde dithioacetals CHs—CH(SR)2, in 40% yield, and acetylene, on being heated at 170—180 °C in the presence of KOH, through synchronous intramolecular transfer of hydride and thiolate. 

A soln. of TiGl4 in 1,2-dichlorethane added dropwise to allyl mercaptan, then acetaldehyde added with continued stirring acetaldehyde diallyl mercaptal. Y 92%. F. e. s. P. Mastagli and Y. Langlois, G. r. 258, 2092 (1964). 

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