Make the simple syrup: Bring 1/2 cup water and the sugar to a simmer in a saucepan over medium heat. Cook, stirring, until the sugar dissolves. Let cool. (You should have about 2/3 cup syrup, enough for 10 cocktails.)
For each drink: Muddle the pineapple, sage and 1/2 ounce of the simple syrup in a shaker with the handle of a wooden spoon. Add the tequila and lemon juice, fill with ice and shake well. Strain into a chilled coupe glass.