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Abstract. Kunzite, the pink, manganese-bearing variety of spodumene, is strongly luminescent under UV or electron beam excitation. Laser excitation of an oriented kunzite single crystal has been used to determine the polarization dependence of the luminescence. The emission spectrum, assigned to an Mn 2 § center, can be fitted by two Gaussian bands with maxima at 16568 and 15 679 cm-1. Analysis of the temperature dependence of emission intensity and band width give estimates of the frequency of the phonons assisting the luminescence transitions. These appear to be bond stretching modes of the octahedral site. Analysis of the polarization dependence of emission intensity allows determination of the orientation of the emission dipole. Comparison of the polarization dependence of excitation and emission radiation shows that coupling between absorption dipole and emission dipole is incoherent.

This paper describes the formal total synthesis of (+)-neopeltolide, a cytotoxic macrolide isolated from the marine sponge Neopeltidae. The key features of the synthesis include an asymmetric Evans alkylation to fix the C9-methyl center, Jacobsen hydrolytic kinetic resolution of terminal epoxides followed by their regioselective opening to fix the stereocenters at the C11 and C13 positions, respectively, a Pd-catalyzed oxa-Michael reaction to construct the tetrahydropyran ring, and Yamaguchi macrolactonization to form the macrocyclic core of the molecule.