Camphorquinone. preparation

The SSZ-33 zeolite was synthesized using the template molecule derived from 8-keto tricycle [5.2.1.0] decane. The boron containing SSZ-33 was converted to Al-SSZ-33 by a one-step reflux in 1 M aluminum nitrate. The SSZ-35 zeolite was prepared with the template camphorquinone. SSZ-35 zeolite was then subjected to three-fold ion exchange in ammonium nitrate. 

Camphorquinone (2) is most conveniently prepared from (1R,4R)-(+)-camphor (1) by the method of Rupe, and is converted to a mixture of syn and anti monoximes 3 by the method of Cherry, et al.3 The oxime 3 has also been obtained by nitrosation of... 

Composite fixing cements were prepared based on a standard methacrylate mixture and incorporating either the step 1 product or a mixture of camphorquinone and p-N, -d i met h I am i n be nzoic acid ethyl ester using an Exakt Apparatebau model roll mill. Testing results are summarized in Table 1. 

Alternatively, the allylboration of aldehydes 200 with chiral allyl boronates 199a-d (conveniently prepared from camphorquinone in four steps) also provided the optically active homoallylic alcohols 201a-d with high ee in the presence of achiral Lewis acid catalysts. These boronates are relatively unreactive with aldehydes at low temperatures in the absence of Lewis acid catalyst. However, they furnish low to moderate ee for the allylation at higher temperatures. Hall and co-workers were able to increase the reactivity of the allyl boronates at low temperatures by the addition of strong Lewis acids such as Sc(OTf)3 and obtained the homoallylic alcohols with high ee at low temperatures (Equation 9) <2003JA10160>. 

Calcium D-galactonate, I, 70 Calcium D-gluconate, III, 141, 142, 149, 152, 155, 156, 161 IV, 331 Calcium hypochlorite, III, 165 Calcium 2-keto-D-gIuconate, III, 148, 155 Calcium 5-keto-D-gluconate, III, 156 Calcium lactobionate, calcium bromide double salt, III, 155 Calcium Ievulinate, IV, 311 Calcium maltobionate, III, 161 Calcium D-mannonate, III, 152 Calcium pectate, I, 334 Calcium D-rhamnonate, III, 144 Calcium salts, in preparation of aldonic acids with NaCN, I, 23 Calcium vicianobionate, III, 154 Calcium D-xylonate, III, 155 Camphor, optically active, formed from inactive (racemic) camphor carboxylic acid in the presence of quinine, quinidine or nicotine, V, 53 Camphor carboxylic acid. See Camphor. Camphor, 3-hydroxy-, IV, 89 Camphorquinone, phytochemical reduction of, IV, 89... 

Preparation of the Auxiliary. A synthesis of the (1/ ) auxiliary has been reported starting from (-i-)-camphor (eq 1). Zinc reduction of the intermediate imine (2) followed by sulfonylation and ketone reduction with Ca(B 114)2 afforded the cis.endo product in 70-75% overall yield from camphorquinone (1). 

Camphorquinone (249) is responsible for the yellow colour of freshly prepared 3-hydroxymethylenecamphor it is formed by oxidation, and can be made from the hydroxymethylene compound by treatment with a diamine, the resulting bis-aminomethylenecamphor being even more readily oxidized in air. ... 

Two sterically hindered /V-sulfonylated aminobomeols 42 were prepared from camphorquinone 11 and used after esterification for the formation of enolates which are alkylated or oxidized diastereoselectively (Sections D.1.1.1.3.2., D. 1.5.2.1., D. 1.5.2.3. and D.4.I.). The synthesis of these auxiliaries involves the reaction of camphorquinone 11 with 3,5-dimethylaniline to give the mono-imine by reaction with the sterically less hindered carbonyl group, followed by reduction with boranate and reaction with benzenesulfonyl chloride to give the exo.exo-product. or initial reduction with zinc/potassium hydroxide, then sulfonylation, and finally reduction with boranate to give the endo,endo-isomer21. 

Bis[( — )-camphoFquinone-a-dioximato]cobalt(ll) hydrate (1). Mol. wt. 467.42, m.p. 240 241". The chiral complex is prepared by the reaction of CoCIa-OHaO with the a-dioxjme of (— )-camphorquinone. 

Asymmetric aldol reactions. The chiral N-propionyloxazolidinone (1), prepared in several steps from (lR)-(—)-camphorquinone, undergoes highly diastereoselective aldol reactions with the additional advantage of high crystallinity for improving the optical purities of crude aldols. Either the lithium enolate or the titanium enolate, prepared by transmetalation with ClTi(0-(-Pr)3, reacts with aldehydes to form syn-adducts with diastereomeric purities of 98-99% after one crystallization. The observed facial selectivity is consistent with metal chelation of intermediate (Z)-enolates (supported by an X-ray crystal structure of the trapped silyl enol ether). The lithium enolate also exhibits... 

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