Michiyasu Hirama

A new entry into the synthesis of the strychnos indole alkaloids containing 19,20-double bond via the thio-claiser rearrangement

Abstract A simple and selective route to the Strychnos framework containing 19,20-double bond has been developed employing the thio-Claisen rearrangement.

New synthetic route to mono- and di-γδ-unsaturated NN-dialkylthionamides by the thio-Claisen rearrangement based on acyclic NN-dalkylthioamides

Mono- and di-γδ-unsaturated NN-dialkylthiomides have been synthesized by a thio-Claisen rearrangement of α-amino-αβ-unsaturated sulphides derived from acyclic NN-dialkylthioamides.

Nucleophilic displacement reactions of the methanesulfonates of the 1-O-benzoyl-1,2-, -1,3-, and -1,4-glycols

Nucleophilic displacement reactions of the methanesulfonates (8a–c) of the 1-O-benzoyl-1,2-, -1,3-, and -1,4-glycols (7a–c) with potassium acetate in boiling acetic anhydride have been examined. Both benzoyloxy-group participation pathway (path A) and SN2 displacement pathway (path B) have been involved in the 1,2-(8a)- and 1,3-(8b)-substrates to give a mixture of the primary (10a,b) and the secondary (11a,b) acetates with complete inversion of chiralities. On the other hand, only SN2 displacement pathway (path B) has been involved in the 1,4-substrate (8c) to give the secondary acetate (11c) with inversion of the chirality.