Abstract: The synthetic porous crystalline material, MCM-56, is synthesized by a process comprising the steps of:a) preparing a reaction mixture containing sources of alkali or alkaline earth metal (M) cation, an oxide of an trivalent element X, an oxide of a tetravalent element Y containing at least 30 wt. % of solid YO.sub.2, a directing agent (R), and water, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:YO.sub.2 /X.sub.2 O.sub.3 5 to 35H.sub.2 O/YO.sub.2 10 to 70OH.sup.-- /YO.sub.2 0.05 to 0.5M/YO.sub.2 0.05 to 3.0R/YO.sub.2 0.1 to 1.0b) crystallizing said mixture at a temperature of about 80.degree. C. to about 225.degree. C., preferably about 125.degree. C. to about 140.degree. C., to form crystals of MCM-56,c) terminating said crystallization prior to the formation of a significant quantity of MCM-49, andd) separating the MCM-56 crystals from the reaction mixture.