02640nas a2200241   4500008004100000022001400041245014300055210006900198260007700267300001200344490000700356520171700363653001402080653001802094653001902112653001402131653002602145100002102171700002702192700002402219700002502243856013002268       2009                        eng d  a0947-653900aEnhancing intermolecular benzoyl-transfer reactivity in crystals by growing a ``reactive'' metastable polymorph by using a chiral additive0 aEnhancing intermolecular benzoyltransfer reactivity in crystals   aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV  a261-2690 v153 a<p>Racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoacetate, which normally crystallizes in a monoclinic form (form I, space group P2(1)/n) could be persuaded to crystallize out as a metastable polymorph (form II, space group C2/c) by using a small amount of either D- or L- 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoformate as an additive in the crystallization medium. The structurally similar enantiomeric additive was chosen by the scrutiny of previous experimental results on the crystallization of racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoacetate. Form II crystals call be thermally transformed to form I crystals at about 145 degrees C. The relative organization of the molecules in these dimorphs vary slightly in terms of the helical assembly of molecules, that is, electrophile (El)center dot center dot center dot nucleophile (Nu) and C-H center dot center dot center dot pi interactions, but these minor variations have a profound effect on the facility and specificity of benzoyl-group-transfer reactivity in the two crystal forms. While form II crystals undergo a clean intermolecular benzoyl-group-transfer reaction, form I crystals are less reactive and undergo non-specific benzoyl-group transfer leading to a Mixture of products. The role played by the additive in fine-tuning small changes that are required in the molecular packing opens up the possibility of creating new polymorphs that show varied physical and chemical properties. Crystals of D-2.6-di-O-benzoyl-myo-inositol-1,3,5-orthoformate (additive) did not show facile benzoyl-group-transfer reactivity (in contrast to the corresponding racemic compound) due to the lack of proper juxtaposition and assembly of molecules.</p>10aAcylation10acarbohydrates10aCrystal growth10acyclitols10asolid-state reactions1 aMurali, Chebrolu1 aShashidhar, Mysore, S.1 aGonnade, Rajesh, G.1 aBhadbhade, Mohan, M.  uhttp://library.ncl.res.in/content/enhancing-intermolecular-benzoyl-transfer-reactivity-crystals-growing-reactive-metastable-001492nas a2200229   4500008004100000022001400041245011100055210006900166260010600235300001400341490000700355520059600362653002400958653001800982653001301000653002601013653001201039100002801051700002401079700002801103856013101131       2015                        eng d  a0040-403900aSynthesis of naturally occurring (+)-osmundalactone and 4-epi-(+)-osmundalactone from triacetyl-O-D-glucal0 aSynthesis of naturally occurring osmundalactone and 4epiosmundal  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY  a2783-27860 v563 a<p>An efficient total synthesis of (+)-osmundalactone 1 has been achieved starting from readily available triacetyl-O-D-glucal 6 employing Ferrier rearrangement and Jones oxidation as key steps. Also, synthesis of 4-epi-(+)-osmundalactone 2 was accomplished from the common key intermediate 9. The absolute stereochemistry of (+)-osmundalactone 1 and a precursor of 4-epi-(+)-osmundalactone 2 have been established by single crystal X-ray analysis. The overall yield of compound 1 and 2 from triacetyl-O-D-glucal 6 is 13% and 8%, respectively. (C) 2015 Elsevier Ltd. All rights reserved.</p>10aBioactive molecules10acarbohydrates10aD-glucal10aFerrier rearrangement10aPyrones1 aKotammagari, Tharun, K.1 aGonnade, Rajesh, G.1 aBhattacharya, Asish, K.  uhttp://library.ncl.res.in/content/synthesis-naturally-occurring-osmundalactone-and-4-epi-osmundalactone-triacetyl-o-d-glucal-0