Iodocyclization of a series of homoallylic tert-butyl carbonates is an efficient and moderately erythro stereoselective method for the functionalization of homoallylic alcohols with 1,3 relative asymmetric induction. Comparison with the anionic carbonate cyclization process of Cardillo et al.1 234 5reveals a similar stereoselectivity for the two methods. Experiments with a number of carbonate derivatives (tert-butyl, benzyl, and 4-methoxy-and 2,4dimethoxybenzyl) show that loss of the alkyl cation from cyclic intermediate 16 is rate determining. Depending on the cleavage conditions employed, the cyclic iodo carbonates (e.g., 9) can be converted with high selectivity to the iodohydrin methyl carbonate 18, epoxy methyl carbonate 19, or epoxy alcohol 20, offering a significant advantage over our previously reported phosphate cyclization method.

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Although quite an extensive investigation has been done on azetidin-2-ones, only a few papers have been reported on azetidin-3-one derivatives. The compounds which fall in this category are 1-acetyl-2,2,4,4-tetramethylazetidin-3-one,3)1-benzoylazetidin-3-one4) and 1-t-butyl-2,2-dimethylazetidin-3-one.5)However no direct oxidation of 1-alkyl-azetidin-3-ols6) to the corresponding azetidin-3-ones has been reported. This prompted us to attempt the oxidation of some 1-substituted-alkylazetidin-3-ols to the corresponding azetidin-3-ones which might be useful as intermediates in our studies exploring new azetidine derivatives.Treatment of 1-diphenylmethylazetidin-3-ol (Ia)7) with pyridine-SO3 in DMSO and triethylamine for 30 min8) gave 1-diphenylmethylazetidin-3-one (IIa) in good yield.The strucChart 1 1) A part of this paper was presented at the 3rd International

The damage structure of latent tracks in poly(ethylene terephthalate) (PET) has been examined by Fourier transform infrared (FT-IR) measurements. Results are compared with those from previous studies on bisphenol A polycarbonate (PC) and poly(allyl diglycol carbonate) (PADC). These polymers are exposed to protons and heavy ions (He, C, Ne, Si, Ar, Fe, Kr, and Xe) in air with energies less than 6 MeV/n, as well as gamma rays from an intense Co-60 source. Chemical damage parameters, namely, damage density, which is the number of losses of considered functional groups per unit length of tracks, radial size of the track core, in which the considered chemical groups are lost, and radiation chemical yields (G values) for each group are evaluated as a function of the stopping power. It has been confirmed that latent tracks will be etchable when the radial track core size is larger than the distance between two adjacent breaking points of polymer chains. The predominant breaking points are the C–O bonds in ether, ester, and carbonate ester bonds.

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