1,3-Oxathiolane derivatives, process for the preparation of 1,3-Oxathiolane derivatives and intermediates thereof

A process for the preparation of 1,3-oxathiolane derivatives of Formula I

• and pharmaceutically acceptable salts thereof comprising cyclizing, in a first solvent and in the presence of a first acid, a compound of Formula VII
• or a salt thereof and optionally adding an acid of a pharmaceutically acceptable salt wherein
• R2 is alkyl, substituted alkyl, aryl, substituted aryl, or arylalkyl;
• R3 and R4 are independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, or arylalkyl;
• and either
• (i) R5, R6 and R7 are independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, or substituted arylalkyl provided that at least one of R5 and R6 is alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, or substituted arylalkyl;
• (ii) R5 and R6 form a ring group together with the carbon to which they are bonded and R7 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl arylalkyl or substituted arylalkyl;
• or
• (iii) R5 and R7 form a ring group together with the carbons to which they are bonded and R6 is hydrogen, alkyl, substituted alkyl, aryl, substituted aryl arylalkyl or substituted arylalkyl.