The preparation of ((CH3)2CHS)2AlCH3 and (t-CaH9S)2AlCH3 is reported. The reactions of (RS)2AlCH3 (R = CH3, (CH3)2CH, t-C4H9) with ketones give aldol condensations leading to the corresponding conjugated ketones, with the acetyl group R—CO—CH3; with other ketones, a mixture of thioacetal and enolthioether is obtained. With aldehydes, a mixture of thioacetal and enolthioether is observed. With olefins there is an addition of two RS groups on the site of the double bond, with a small percentage of allylic substitution. With conjugated ketone, the saturated ketone is obtained with the alkylthio group in β position. All those reactions proceed with good yields and appear quite general.