Preparation of Pyranose‐Based Thioimidate N‐Oxides (TINOs)

Abstract

The synthesis of new pyranose-based thioimidate N-oxides (TINOs) is reported. Original strategies were developed, by taking advantage of the nucleophilic capability of the thiohydroximate function, anchored on a carbohydrate backbone. The key cyclisation step was achieved either through a Mitsunobu-type reaction or through desilylative cyclisation. These studies enable access to a unique family of polyhydroxypiperidine thioimidate N-oxides both from aldo-

Total Synthesis of (−)-Carinatine A and (+)-Lycopladine A

“…Finally, hydroboration-oxidation of terminal olefin moiety in 4 produced alcohol 22 , which was subjected to reductive removal of oxime with TiCl 3 to furnish (+)-lycopladine A ( 2 ) . We also observed the isomeric lactol form 23 coexisting with 2 as reported previously. , In a parallel procedure, intramolecular Mitsunobu reaction of 22 with n -Bu 3 P and 1,1′-(azodicarbonyl)­dipiperidine (ADDP) afforded (−)-carinatine A ( 1 ) . The analytical data of these two synthetic compounds were identical with those reported.…”

“…6b,d In a parallel procedure, intramolecular Mitsunobu reaction of 22 with n-Bu 3 P and 1,1′-(azodicarbonyl)dipiperidine (ADDP) afforded (−)-carinatine A (1). 15 The analytical data of these two synthetic compounds were identical with those reported.…”

Thiohydroximic Acids: Versatile Reagents for Organic Synthesis

“…This reaction was recently expanded to the formation of sugar-derived six-membered-ring thioimidate N-oxides. 20 The previous Mitsunobu cyclization strategy was unsuccessful for the six-membered-ring formation; therefore, the authors adapted a fluoride-mediated desilylative S N 2 ring closure (Scheme 4, eq. 3) that had been developed by Tamura for the synthesis of six-membered-ring aldonitrones.…”