Crystal Structure of (1R,2R,3S,4S,5S,6S,7R,9S)-6-Azido-7-cyano-3-C-hydroxy-methyl-3,3′-di-O-isopropylidene-9-methoxy-2,4,5-tris(O-methoxymethyl)-2,3,4,5-tetrahydroxy-8-oxabicyclo[4.3.0]nonane, toward Tetrodotoxin

Non-classical hydrogen bonding involving bound diazides in an inositol derivative

“…There are few cyclohexane structures in the Cambridge Structural Database (CSD, Version? ; Allen, 2002) with adjacent azide and O substituents, namely CSD refcodes QAPSAB and QAPSEF (Akai, Nakamura et al, 1999;Akai, Sugita et al, 1999), AZUZAW (Busscher et al, 2004) and IXEVAI (Carballido et al, 2004). The azide angular geometries C1-N1-N2 and N1-N2-N3 in (I) fall within the previously observed ranges of 114-119° and 170-174°, respectively.…”

Stereoselective and Efficient Total Synthesis of Optically Active Tetrodotoxin from d-Glucose

“…The reaction of α-azido-aldehyde 22 and TMS−CN/Et 3 N in MeOH gave the corresponding cyanohydrin 23 and its epimer 23a in 56% and 17% yields, respectively. The stereochemistry at C -6‘ ( C -9 in TTX numbering) of 23 was the same as that observed in the total synthesis of (±)-TTX . The undesired isomer 23a could be isomerized into the desired isomer 23 under the same reaction conditions.…”

“…We have been engaged in the total syntheses of naturally occurring branched-chain cyclitol compounds such as cyclophellitol, mytillitol, laminitol, and (−)-TTX 18 starting from d -glucose. On the basis of these investigations, we have recently accomplished a novel and stereoselective synthesis of (±)-TTX from myo -inositol . Herein, we describe the total synthesis of optically active TTX from d -glucose employing the Henry reaction (Nitro aldol reaction) as the key transformation.…”

“…Scheme shows the retrosynthetic plan for the synthesis of (−)-TTX from d -glucose, which focuses on the preparation of the key intermediate, ketone D . This intermediate has previously been successfully converted to TTX in our laboratory . In a previous work, we synthesized (±)-TTX via compounds A , B , C , and D .…”