Zeolites X, Y, and DAY have been modified by a post-synthetical dealumination procedure to generate mesopores that are completely surrounded by micropores. In these novel host materials several bulky transition metal salen complexes have been occluded via the "ship-in-a-bottle" synthesis approach. Both the host materials and the "ship-in-a-bottle" catalysts have been characterized by FTIR spectroscopy and nitrogen adsorption. Additionally, the "ship-in-a-bottle" catalysts have been characterized by thermogravimetric analysis and ICP-AES spectroscopy. The catalysts have been tested in the stereoselective epoxidation of R-(+)-limonene and (-)-alpha-pinene with molecular oxygen as oxidant. The best results so far - 100% conversion, 96% selectivity and 91% de - were achieved with the immobilized (R,R)-(N,N')-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethylene-1,2-diaminocobalt complex in the epoxidation of (-)-alpha-pinene.