Camphor, -2-hydroxymethylene

The zinc complex of 1,1,1,5,5,5-hexafluoroacetylacetonate forms coordination polymers in reaction with either 2,5-bis(4-ethynylpyridyl)furan or l,2-bis(4-ethynylpyridyl)benzene. The X-ray crystal structures demonstrate an isotactic helical structure for the former and a syndio-tactic structure for the latter in the solid state. Low-temperature 1H and 19F NMR studies gave information on the solution structures of oligomers. Chiral polymers were prepared from L2Zn where L = 3-((trifluoromethyl)hydroxymethylene)-(+)-camphorate. Reaction with 2,5-bis(4-ethy-nylpyridyl)furan gave a linear zigzag structure and reaction with tris(4-pyridyl)methanol a homo-chiral helical polymer.479... 

By means of sodium ethylate or sodium, Claisen prepared hydroxymethylene camphor by condensing camphor with amyl formate 27... 

By the reaction of theenolatc of camphor with carboxylic acid esters or chlorides, 1,3-diketones [better formulated as enols. such as (hydroxymethylene)camphor] are obtained. When trifluo-roacetic acid or heptafluorobutanoic acid are used, the corresponding diketones (abbreviated as tfc or hfc, respectively) have been successfully used as ligands for lanthanides and these are used as chiral shift reagents in NMR spectroscopy12. The complex Eu(hfc)3 [derived from ( + )-camphor)] 3 was used as a chiral catalyst for enantioselective Diels-Alder-type cycloadditions of aldehydes to dienes (Section D.l.6.1.1.1.2.4.). 

Hydroxymethylene camphor phosphinic acid, CioHi40=CH. P0(0H)2, is isolated as a by-product in the preparation of hydroxymethylene camphor by treating oxymethylene camphor (3 mols.) with phosphorus trichloride (2 mols.). It crystallises with half a molecule of water, which may be expelled at 110° C. The ammonium, silver and lead salts are known, also the following derivatives oxychloride, CioHi40 = CH.POCl2, white tablets, M.pt. 51° C, B.pt. 175° to 180° C-., decomposed by water aniline salt, M.pt. 195° to 196° C. anilide, slender yellow needles, M.pt. 227° to 228° C. p-toluidide, M.pt. 210° C. p-phenetidide, M.pt. 137° C. diethyl ester, B.pt. 195° to 205° C. at 20 mm., decomposed by water. 

Compounds derived from Aldehydes and Ketones Reaction between PCI3 and Unsaturated Ketones, Mechanism of Reaction of PClj with Benzaldehyde, 1 4 Addition of Phenyldichlorophosphme, Interaction of Phosphorus Halides with Distyryl Ketone and Phenyl Cinnamylidene Methyl Ketone, Action of PCI3 on turated Aldehydes and Ketones, Interaction of Di-phenylohlorophosphine with Benzaldehyde and Benzal etophenone, Addition of Alkoxy- and Aryloxy-chlorophosphines to Carbonyl Compounds— Phosphorus Derivatives of Dimethylaniline— Derivatives of Dibenzyl-methane and Hydroxymethylene Camphor— Heterocydio Rings containing... 

The compounds separate from the condensation as sodium salts. From the simple ketones, the compound formed is not stable and undergoes change on precipitation from its sodium salt. The formation of a hydroxymethylene compound is used as proof of the presence of the group—CH2—CO—in camphor. The following preparation shows the details of the method. 

Chiral shift reagents are also tris jS-diketonates based on d-camphor as the chiral moiety. Whitesides and Lewis (1970) introduced the tm[3-(rerf-butyl-hydroxy-methylene)-d-camphorato] europium. It is more soluble in organic solvents than Eu(dpm)3 with otherwise similar chemical properties. Fraser et al. (1971) prepared a fluorinated derivative anticipating advantages similar to those of R(fod)3 relative to R(dpm)3. Indeed their fWs[3-(heptafluoropropyl hydroxy-methylene)-d-camphorato] europium induces larger chemical shift differences between enantiomers in most of the cases. Even larger differences were obtained with fn. 5[3-trifluoromethyl-hydroxymethylene)-d-camphorato] europium (Goer-ing et al., 1971). 

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