3-Hydroxy-2-hydroxymethyl-6-substituted

Potassium fluoride is of limited value in the field of steroids. It has been used to substitute hydroxy groups in 6a- and 16a-hydroxymethyl-substituted steroid.s. as well as for the synthesis of 16-fluoro-17-oxo- and 21-fluoro-20-oxo-substituted steroids.In the latter case. 17,21-oxides are formed as byproducts due to the basic strength of the fluoride ion. 

Pyrrole, 3-hydroxy-geometry, 4, 158 synthesis, 4, 343 tautomerism, 4, 36, 198 Pyrrole, 3-([Pg.816]

The CBi binding affinity of the hydroxymethyl and carboxyl analogues can be increased by substituting the C3 pentyl side chain for a dimethylheptyl side chain (Table 6.13). 1 l-Hydroxy-l, l -DMH A -THC, HU-210 (165), is an extremely potent cannabinoid agonist that has been widely used as a pharmacological tool [119]. Its ( + ) enantiomer, HU-211 (dexanabinol), which is in clinical development for the treatment of cognitive disorders, does not have high affinity for CBi receptors [120]. 

Stepanov et a/.143,144 report the ring opening of the monoxide (116) to several 2-oxaadamantane derivatives, where 116 is readily obtained by perbenzoic acid oxidation of 35. Treatment of 116 under various conditions yields different products. Thus, with aqueous acid it yields l-hydroxy-3-hydroxymethyl-2-oxaadamantane (117), with alcohols (R = CH3, C2H5) in acidic or basic media 1-alkoxy-substituted (118), and with hydrochloric acid l-chloro-3-hydroxymethyl-2-oxaadamantane(119). l-Methyl-2-oxaadaman-tane (120) is prepared by LAH reduction of the carbonyl group in 35 to alcohol 121 and subsequent cyclization with acid.140,142... 

The photoinduced-addition of alcohols to cycloalkenones has been investigated by Fraser-Reid and co-workers,4 by Paquette,5 and was used as the key step in the synthesis of the prostaglandin endoperoxide analogue (15S)-hydroxy-9a,11a-epoxymethanoprosta-(52,13E)-dienoic acid,6 and for the recent synthesis of 2, 3 -dideoxy-3 -hydroxymethyl-5 -carbanucleosides.7 No work (other than our own) has been reported on the photoinduced-addition of alcohols to 5-substituted furan-2(5H)-ones. 

The reactions are those of functionalized 1-alkynes, the first of which were described for alkynes bearing substituted hydroxymethyl groups, such as substituted propargyl alcohols, HC=CCRR (OH), and often proceed further to form metal allenylidene complexes, by spontaneous dehydration of a (usually unobserved) hydroxy-vinylidene complex (Equation 1.22) ... 

Hydroxypyridine reacts with formaldehyde and base to give the 2-hydroxymethyl derivative which reacts further, ultimately to yield the 2,6-disubstituted product. No 4-substitution is detected in this case or with 3-hydroxy-2,6-dimethylpyridine when it is treated under the same conditions (75RCR823). 3-Hydroxypyridine readily undergoes bis-aminomethylation at the 2- and 6-positions. 

Chelating alkylphosphanes that are water soluble by virtue of having hydroxy end groups were reported recently. The catalytic formylation of H2PC6H4PH2 and of H2PCH2CH2PH2 in the presence of formaldehyde in aqueous media yields hydroxymethyl bis(phosphanes) in near-quantitative yields (54). Hydroxypropyl-substituted compounds were prepared by radical addition of allylic substrates to 1,2-diphosphinoethane in methanol (55). 

As discussed previously (Section 3.3.3.1), halomethyl, hydroxymethyl and aminomethyl groups show enhanced reactivity toward nucleophilic attack because of the ease with which the halogen, hydroxy or amino group is lost in (321). Both side-chain (322) and nuclear substitution products (323) have been obtained (Scheme 61). These two possibilities are exemplified by the reaction of furfuryl chloride with sodium cyanide to give (322a) and (323a). 

Although the hydroxy group is a relatively poor leaving group, its base-catalyzed nucleophilic substitution by the mechanism shown in Scheme 69 accounts not only for the hydrogenolysis of the 3-hydroxymethylindoles, but also for their SN reactions with ethoxide ions, cyanide ions and with piperidine. Nucleophilic substitution on 2-hydroxymethyl-pyrroles is generally precluded by the faster formation of the bis(2-pyrrolyl)methanes, but the synthesis of 2-cyano-2-(2,5-dimethyl-3-pyrroIyl) propanes from 2,5-dimethylpyrrole, propanone and potassium cyanide probably results from an SN reaction of the cyanide ion upon the initially formed 3-pyrrolylcarbinol (81USP4248784). The formation of (294)... 

---