1.3- Diol monotosylate

The analogous A-nor yi ws-diol monotosylates have also been converted into oxetanes [J377. No fragmentation of the ring occurred because the geometry of the five-membered ring does not permit the necessary. coplanarity of the C(5>-C(3) C(2) OTs system. 

Solvolytic Reactions.—further study is reported of the curious formation of the 3j8,5)5-oxetan (100) by solvolysis of the (cis)-3, 5)S-diol monotosylate (99). The (trans)-3o,5j8-diol 3-tosylate solvolyses at only 1/19 the rate found for the cis-isomer. Only the latter gives the oxetan, and the higher rate is thought to result largely from relief of steric compression, rather than from anchimeric... 

Cyclic ethers from diol monotosylates 236. HOv. ..CH2CH2OTS... 

A soln. of bicyclo[5.3.1]undecane-8a,lla-diol monotosylate in 1,2-dimethoxy-ethane added during 0.5 hr. to a soln. of LiAlH4 in the same solvent, and the... 

Figure 2 shows time conversion curves of 7 in CIXI3 at 100 C. In the absence of TsOH, the disappearance of the diol monotosylate star aft heating for 200 min or longer and occurred in a non-linear manner. The addition of TsC resulted in the marked reduction of heating time for the abrupt consumption of 7, indicating that the acidolysis reaction of 7 t es place autocatalytically. The determination of product distribution showed that 2-phenylcyclohexanone-l and benzoylcyclopentane are obtained in 36 % and 44 % yields, respectively, while TsOH is formed almost quantitatively (Scheme 4). Considering the chemical structures of the ketonic products, it is very likely that 7 imdergoes pinacol-type rearrangement...

Figure 5 Photosensitivity curves for poly(ter/-butyl methacrylate) photoactivated by 2 mol% of 8 in the absence (-0-) and in the presence of 5 mol% (- -) 10 niol% (- -) and 15 mol% (-A-) of diol monotosylate (7) as an acid amplifier. Post-exposure bake 100°C for 1 min, development 3 wt% of Me N OH.

It was found that the addition of these add amplifiers to conventional chemically amplified photoresist systems results in marked enhancement of photosensitivity characteristics. A photoresist based on a ternary system consisting of pBOCSt, the acetoacetate-type add amplifier (2a) and PAG exhibited enhanced deprotection during post-exposure bake irrespective of the nature of PAG. Marked improvemoit in photosensitivity was observed when the ketal-sulfonate-type add amplifier (3) or the diol monotosylated-type add amplifier (7) is embedded in a thin film of poly(ter/-butyl... 

Monocyclic ethyleneketones from bicyclic diol monotosylates s. 19, 937... 

Lithium perchlorate calcium carbonate Ring expansion of isocyclic diol monotosylates Q)... 

Cyclization. A new approach to the synthesis of oxaziridines involves the reaction of tosyl chloride in aqueous alkaline solution with a cyclic nitrone this reaction appears to be mechanistically similar to the cyclization of diol monotosylates in epoxide synthesis. This method has been applied to heterocyclic steroidal nitrones (276). ° Photo-oxidation of cyclohexylamine may... 

Scheme11.4 Applications of chiral styrene oxides and 1,2-diol monotosylates to the synthesis of some chiral drugs.

The base catalyzed rearrangement of a monotosylated 1,2-diol on alumina, followed by immediate condensation of the sensitive ketone with methylenetriphenylphosphorane, gave the exo-methylene compound below (G. Btlchi, 1966B). 

Base catalyzed pinacol rearrangement of vicinal m-glycol monotosylates is a simple and useful general method for preparing perhydroazulenes. Thus, treatment of cholestane-5a,6a-diol 6-tosylate (115a) with either one mole-equivalent of potassium t-butoxide in f-butanol at 25° or with calcium carbonate in dimethylformamide at 100° gives a quantitative yield of 10(5 6/5H)... 

Diols or (3-hydroxy ethers are particularly useful substrates for fragmentation. If the diol or hydroxy ether is converted to a monotosylate, the remaining oxy group can promote fragmentation. 

A rapid one-pot method for converting 1,3-diols into oxetanes by the intramolecular Williamson reaction has recently been described. The monolithium salt is generated by treatment of the diol with one equivalent of butyllithium in cold THF, followed by addition of one equivalent of tosyl chloride to give a monotosylate, which is cyclized by addition of a second equivalent of butyllithium (equation 83). Yields of 70-90% are reported for a variety of alkyl- and aryl-substituted oxetanes (81S550). Another simple method for converting 1,3-diols into oxetanes consists of converting them to cyclic carbonate esters by ester... 

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