Bring sugar and water to boil in small saucepan, stirring to dissolve sugar. Add rosemary sprigs. Reduce heat and simmer 2 minutes. Cool mixture completely. Discard rosemary.
Mix rosemary syrup, vodka, lemon juice, and brandy in large pitcher. Cover pitcher with plastic wrap and place in freezer until mixture is cold, about 3 hours. Remove pitcher from freezer; add ice cubes. Stir briskly to melt ice partially. Strain mixture into chilled Martini glasses. Garnish each glass with rosemary sprig.
