First, we have selected 2-methyl-2-(naphthalen-2-yl)-1,3-dithiane 1a which was totally reduced into 2ethylnaphtalene by TMSCl/NaI combination in CH2Cl2 [Error! Bookmark not defined.] as our model substrate to herein examine the dithiane deprotection reaction by the same reagents under a variety of reaction conditions (Table ). In view of using EtOH as a green solvent, we firstly try to deprotect 1,3dithiane 1a in EtOH in the presence of 10 equiv. of TMSCl/NaI combination. However, EtOH and other alcohols of different nucleophilicity as trifluoroethanol (TFE) or tBuOH were found to be ineffective as 1a was mainly found unchanged after 24 h of reaction at rt (entries 1-3). When the deprotection-reactions were done in Et2O, THF or acetone (entries 4-6), a better trend was noticed since 2b was isolated in low yields accompanied by a large part of unreacted 1a. Longer reaction times or higher temperatures will probably be needed to complete this transformation in these solvents. In CH3CN, in which the nitrogen atom is linked to the silicon atom of TMSCl, we were pleased to isolate 2a with a promising yield of 52 % (entry 7) with no trace of the reduced 2-ethylnaphtalene obtained in CH2Cl2. [Error! Bookmark not defined.] Under same reaction conditions but without NaI, 1a was found unchanged thus showing the essential role of NaI (entry 8). Addition of water, NaOHaq or HClaq had a deleterious effect on the reaction since a large part of 1a was recovered after 24 h of reaction (entries 9-12). The amount of TMSCl/NaI and the temperature of the reaction were next examined (entries 13-17) and the best result was obtained by achieving the deprotection reaction at 60 °C in the presence of 20 eq of TMSCl/NaI leading to ketone 2a in an excellent yield of 92% (entry 17). To examine the influence of solvents (deprotection vs reduction), 1a was reacted with TMSCl/NaI in CH3CN/CH2Cl2 (1/1) for 24 h at 60 °C (entry 18). In this mixture of solvents, we have isolated only ketone 2a (85 %) with no trace of the 2-ethylnaphtalene (reduced compound) showing the predominant role of CH3CN when linked to TMSCl (see plausible mechanism in Scheme 4). Last, the reaction was also run in CH3CN in the presence of TMSI (10 eq) at rt (entry 19) for comparison. After only 3 h of reaction, we observed by TLC the total disappearance of 1a but 2a was isolated, beside a large number of unidentified by-products, with a poor yield of 10% thus showing the superiority of the TMSCl/NaI association compared to TMSI for carrying out these deprotection reactions in CH3CN.