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A new and efficient synthesis of branched-chain cyclitols and their congeners utilizing a stereospecific Claisen rearrangement is reported.Almost twenty years have passed since Michell's suggestion1 that the phosphoinositide cascade is associated with cellular Ca2+ mobilization. Subsequently, Berride et a1.2 and Nishizuka3 identified D-myo-inositol 1,4,5-trisphosphate

The carbocyclic analogue (VII) and the carbocyclic nor‐analogue (VIII) of MDP (IX) are prepared in order to modify the immunostimulating activities of this compound.

Synthesis of Carbocyclic Analogues of Lipid X. -The carbocyclic analogue (XIIIa) of lipid X, which contains a methylene group instead of the ring oxygen, is synthesized from (I) as key intermediate in a ten-step reaction in 6% overall yield. The nor-analogue (XIIIb) is obtained by a similar method. Compounds (XIII) inhibit the lipopolysaccharide capacity to induce procoagulant activity and do not induce tumor necrosis factor. -(AUGY-DOREY, S.; DALKO, P.; GERO, S. D.; QUICLET-SIRE, B.; EUSTACHE, J.; STUETZ, P.; Tetrahedron 49 (1993) 36, 7997-8006; Inst. Chim. Subst. Nat., CNRS, 91198 Gif-sur-Yvette, Fr.; EN)